[Theory] Valve notoriously cannot "count to 3" in order to hype up to one, massive, cross-over game.
To some this theory may sound confusing or ridiculous, but hear me out.
I was just today doing bored research on the matter, this video got me thinking.
https://www.youtube.com/watch?v=OAr2kgHBk68 (source).
The numbers do add up suspiciously when thought about. The video above was talking about the odd recurrence that Valve cannot create third installments of game franchises, and I began looking at the myth kind of economically.
Let's add it up: 1st Clue: Valve has been seen to never put out a marketed "Third" installation.
2nd Clue: Valve also shows signs of cross-over universes in most games (TF1 & TF2 disregarded).
3rd Clue: Valve goes quiet for a lot of time, not releasing many large games (since Portal 2 mostly, Abstract disregarded.)
4th Clue: Valve has begun 'hoarding' a lot of dough, with focusing on managing steam instead of releasing games.
5th: With all knowledge, make assumption that Valve may be preparing one massive, history-making game with earnings to go down in the books or change humanity- a good marketing tactic.
Conclusion: If Valve is being this honorable, and not just hoarding and cashing out on Steam, we can begin to prepare for what explosion may come in the future years...