Video games are not like movies, not like content. Since their inception, 1% of the games get 99% of the players. For example, when half-life was released, everybody was playing half-life. In this environment, you can't simply make another fps with a cool scenario and expect it to be a hit. You have to have real hard innovations in your product. A look at the big trends since 30 years clearly shows it. For example, in 2000, 50 games were high-grossing hits over a total of 5000 games that were produced that year [1]. You may think, well, cool story bro but what about Ubisoft for example, they are doing games like content. Most companies that did or do video games like it's content have or will disappear (the data show it all). Now, there is a business in pissing video games like content, but there is only spots for a few big conglomerates that will profits from the quantity, not the quality.

This is in my opinion the reason why Valve is having a hard time doing a new game, not because they don't want to. They want to be Valve and make good games, even if it means waiting years before an opportunity presents itself.

[1] https://www.amazon.com/Citizen-Game-French-Nicolas-Gaume/dp/...