Because I for one am not making any of that money and I want a new Portal game, damn it.
With games, you seem to have two choices...
Do you want a game now, or a genre defining masterpiece that maintains playability for a decade later?
Now an actual Half-Life 3 in VR, on the other hand ... if executed properly that would literally go into the history books as launching the entire next generation of gaming, more different in kind than even the original transition from sprite-based to truly 3D-rendered environments.