I can see it now. Valve releases TF2 match making tomorrow. The gaming community shits their pants because their beloved hat simulator can finally be played in a pseudo competitive environment so they can tell themselves they're good. The game grows exponentially overnight surpassing CSGO almost instantly.
Over the course of the next month TF2 overtakes Dota 2 in numbers. Valve cancels The International and creates The TeamFortress Matchmaking Extravaganza Tournament. The entire Dota 2 dev team leaves Dota 2 for TF2 because people at Valve can work at whatever they want for some stupid reason. The 2 CSGO devs and the 1 intern also migrate to TF2 after realizing what a unique opportunity they've been presented with. After seeing their peers make such a leap, every single employee of Valve starts to work on TF2. With no one working on any other games or projects, all Valve franchises die except for glorious TF2. Valve renames themselves to TeamFortress Inc. Source 2 is never released, but it's for the best, because that is part of the charm of TF2, hitting half the shots you didn't deserve and missing half the shots you did.
President Obama realizing what a unique and fantastic game TF2 is declares April 30th TF2 day stating, "I have never in my life played such a fine game with such an abundance of hats, it is my honor and privilege to declare this glorious day that TF2 matchmaking was released, TeamFortress day, and the following 9 days will be named after each class, and there will be massive parties on every street corner in the United States which I will pay for myself, and by myself I mean I will tax you more".
2 years since TF2 matchmaking was released it is a worldwide sensation. There are no more sports, no football, no soccer, no baseball, everything is gone, there is just TF2. The prize pool for The TeamFortress Matchmaking Extravaganza Tournament's increases to 11 billion dollars. Entire lives are dedicated to the game of TF2, perfecting the art of rocket jumping, or right clicking to blow up some stickies, or flicking your mouse at air but getting the hit because his hitbox is actually there server side. The game seems to have no bounds.
3 years later Gaben is voted president of the world, garnering 8.5 billion votes in favor of him. The remaining 500 million people are then executed.
1 year later Gaben's impending heart disease finally catches up with him. The world weeps as they await the terrible news of the passing of their leader. Gaben is surrounded by his 600 children, all with prostitutes, and smiles seeing how the world has changed for the better because of him, but weeps knowing that no one can replace him. As he prepares to take his final breath a light shines down from the heavens. God himself speaks. "Gabe Newell, you are a man of infinite worth to this world, your accomplishments in life has touched the lives of 9.5 billion people...and I hope that your accomplishments in death will do the same." Gaben slowly lifts out of his bed, drifting towards the sky. His 600 children stand in shock not being able to process what is happening. But Gaben can. He knows that he has achieved godhood. As he makes his way to the heavens he looks back as a mortal being one last time, smiles down at his children, and says his final words. "Tomorrow is the release date of Half Life 3." And with that he departs.
Or the game will die because it's shit.