Tholewhy is it so hard for game devs to not fuck up horribly
even csgo, LoL, and overwatch devs are awful. the only times they added a new gun, champion, or hero, they were extremely overpowered and broken.
Because devs spend their time making the game, not playing it and so compared to top competitive players they're dogshit awful. That's why devs with atleast half a brain have a beta for their games to test new weapons/heroes/general balance changes and its working pretty well for Overwatch (I don't know shit about those other games tho xd). They also gather feedback from the community (generally the competitive community) on what needs to change.
These are all things the TF2 team does not do, or have done in the past and decided were not worth their time (balance changes in the beta, which ended when Valve shut the TF2 beta down).