I apologize in advance, my response will span over multiple posts.
aatjeWe see this exact sort of approach in the popular MOBAs. League of Legends has more than a hundred champions, each with different abilities, strengths and weaknesses... Just as in the absurd soccer hypothetical, direct competition between human beings is reduced by all this other stuff, by these impurities.
CS:GO is impure in a different way. CS:GO has a variety of weapons and grenades, but FPS's probably need a variety. Rather, CS is impure because of its economy. The economy reduces direct competition between players because in a majority of rounds teams do not have equal or equivalent equipment. This means not only are the players competing against each other, the guns and grenades are competing against each other. Just like the champions, or the random crap in the soccer hypothetical, the presence of additional factors is cluttering and crowding out direct competition. This is what we walk about when we talk about impurities.
CS:GO and LoL may both be "impure" but you're missing the biggest point. They've gotten MUCH more popular than TF2 both in casual comp and in tourney play. Those are two of the biggest e-sports of all time so obviously "purity" isn't stopping people from having fun playing it. E-sports are different from real sports, which I will go into more later.
aatjeThe vital difference is that in TF2, you don't buy Soldiers and Scouts, or Medics and Demomen, and you can't have three scouts or two medics because you have more money. Clockwork and b4nny never have to run out to mid with pistols against their opponent's scatterguns because their team is eco-ing a round. They are always competing directly against their opponents. That is the purity of competitive TF2. Everything is always the same. That allows the actual players to create all of the differences.
Perhaps one of the most telling issues with "everything is always the same" is that once things are strategies are standardized things don't usually change that much. I'm one of the people who can appreciate the slight differences made by individual skill, but a large majority of the audience can't see that in every single game. Sure they may appreciate skill, but after you've watched hundreds of casts it really does start looking very repetitive. I don't blame anyone for getting bored watching a game that doesn't leave too much room for innovation. When developing a strong e-sport, one of the most important things you can do is
I'll discuss at least one reason why real life sports can get away with it later.
aatjeMost rounds of CS:GO feature one team having superior equipment than their opponent and some aspect of worrying about preserving equipment. TF2 players never have to back away from a fight to save a sticky launcher. If you don't understand this argument about purity and directness, consider that most CS:GO matches feature multiple rounds where a player chooses not to fight his opponent in order to save his own gun. In these common situations, the game encourages non-competitiveness. Even the best player in the world would be sometimes recommended not to try his hardest to win the round, because of the way the economy works in the game.
I disagree with this point completely. You'll frequently have TF2 players backing off of fights so they can defend the next point. Dying puts a player completely out of play for quite a few seconds which can be a huge penalty just as losing powerful weapons in CS:GO can be. Even the best medic or demo in the world will be recommended to back off from a lost mid-fight to help stop the enemy from rolling quickly to last, because of the way respawn timers works in the game.
aatjeLoL is truly ridiculous with the limits it pushes impurities. At least in CS:GO, teams switch sides at the half. In LoL, whatever champion differences exist last through the entire match. Analysts frequently say a given match was won in the pick/ban phase. Consider how ridiculous that is! LoL is a game where it's valid to argue the match was decided before it was played. That's the complete opposite of direct competition. The competition between players was literally prevented by the advantage one team had from their champion selections.
But LoL is one of the most successful e-sports of all time. Its "impurity" is obviously not stopping people from having fun playing it.
aatjeA version of competitive TF2 where strategy is about gaining advantage with your weapons is a version of competitive TF2 where teams are actively seeking to minimize direct competition between players. In some respect, that's all that strategy is: gaining advantages beyond of skill level. That means the more strategy in a sport, the less direct competition that sport has. In a way, strategy is an impurity. It's all about efficiently and elegantly creating strategic options without adding bullshit like a hundred champions or a hundred weapons.
Regardless of how many champions or weapons you add, people will still choose which are best in a certain situation. The second a meta is established (which happens really, really quickly), the game goes back to being about the players' individual skill and ability to adapt.
aatjeCompare Tennis and American Football. Tennis of course still has a great deal of strategy, and any fan can recall the way Nadal deliberately attacks Federer's backhand. Boxing is similar. Boxing and Tennis have a ton of strategy. But the NFL, by comparison, has a ton of tons. 90% of the NFL's millions of spectators can understand no more than 10% of the strategic levels the game is operating on, all the myriad the schemes and playcalls. LoL is similar.
Of course, the NFL and LoL are wildly popular. But so are the World Cup and Wimbledon. It is safe to say that competitive TF2 is not wildly popular. That doesn't mean it needs to be changed.
Real life sports are popular largely because love for the game is handed down from one generation to the next. Those who have fathers who love watching baseball will most likely love baseball themselves. Real life sports become a lot more just the game itself, from the audience side of things (which is arguably the most important aspect of things like the NFL) the game isn't so much about an individual person's skill or "pure" gameplay as it is generating experiences and memories with close friends and family. Sports are a cultural phenomenon that lasts and grows through generations.
Video games literally just do not last long enough for that to happen. New games come out very frequently and those that have stuck around (Counter Strike, TF2, Starcraft) have only been around for 10 years. They have only reached any sembelence of popularity in the west during the last 3-4 years which isn't enough time to grow up with it then pass it down to your children. When e-sports become an ingrained aspect of a widespread culture experience, that's when you can deal with "purity" and your "purity" arguments start taking hold.
Until then, it only limits innovation and growth in a field that has a lot of competition. Products and businesses don't last long in the world if they only cater to their small niche and don't constantly work to evolve and improve on themselves.
Real life sports and e-sports are entirely different beasts at the moment. It is idiocy to ignore decisions that are successful in e-sports just because you disagree with them.