The sales numbers would be ok if there wouldn't have been such a huge hype for VR few years ago.
Many people on the Internet in forums, tech magazines, Youtubers and so on. They did a lot to tell people that VR is the thing you need to own and some years later you realize that even many hardcore fans didn't buy it. Those who spend thousands for gaming every generation.
And since you can/could try it out in many stores, I'm sure many have tried it out already.
I think VR is a great technology and hope next generation will still support it with even better headsets but right now it seems that not too many people think that VR is more than just something to have fun with for a few hours and be done with it then.