Is there more explanation on this? I thought that Valve employees did that whole roll-the-desk thing to work on whatever they wanted, and that most of them simply chose to work on other projects.
Or does this statement just mean hiring is a decision made by higher ups?
If you watch the video he basically says they don't specifically hire people to work on TF2, and if the TF2 team got a size expansion then the DOTA and CSGO team would also have to get a size expansion.
Valve is moving into a new, much larger office later this year, hopefully after that they hire more developers and some of them choose to work on TF2.