They probably went into VR because if VR became the dominant way of playing games, it would eat their existing business. It's similar to why they made SteamOS as an insurance policy against Microsoft locking them out of the Windows platform.
I think it's safe to say now that VR won't replace PC gaming on a monitor, certainly not any time soon. But since their existing business is doing fine and they didn't invest more than they could afford, it doesn't matter for them if VR fails or becomes a niche product.
Personally, I think VR becoming a niche product is the most likely outcome. People buy expensive steering wheels or flight sticks to get more immersed in their favorite games and, for certain genres, VR can do the same.