Almost all serious PC gamers I've ever known upgrade their graphics cards every 9 - 18months. Very few serious gamers keep a gaming rig untouched for 2 years.
Also the comments about a screen or a graphics card being used for more than gaming. Again, sorry, but most hardcore gamers have a gaming rig for gaming, and will use a phone/tablet/laptop for their more casual usage. They generally dislike cluttering up their primary machine with office productivity apps, etc.
It's a false comparison. It's like someone owning a car for track racing, and saying: "yeah, the seats are expensive, but they will be useful when driving down to the shops to pick up some milk". Absurd. Sure, people might drive their road legal track car to a car show, or a garage, or a parts shop, or their friends, from time to time, but that's part of the hobby experience - not used as a justification for the parts/modification.
Furthermore, the PS3 was a known quantity because of its predecessors. You could reasonably assume that you could get hundreds of hours of entertainment for that initial purchase. VR is unproven and the asking price is just too steep for such a gamble (for me anyway).