I don’t think Valve cares about maximizing sales of this thing. Obviously it would sell more as a non-VR title, but Valve wants to make absolutely the best VR game they can possibly make, and making it non-VR would inherently compromise what they’re trying to do.
There are at least a million Steam users who have VR headsets, and the rate of growth is speeding up, not slowing down:
That number also doesn’t include Oculus Quest headsets, and that thing is selling out worldwide.
It’s not a huge market, but I’m glad Valve has the money to spend on it anyway.