It's more of a platform than an accessory, it just happens to have dependency issues.
And VR is going to be refreshed like cellphones. Expect new models every 9-12 months, for sure. Maybe not for PS VR seeing as their's is a unique position, but definitely for Oculus and Vive. Every tech breakthrough is going to improve comfort and immersion substantially, so much so that no one will want to use or return to older devices at all. But price is going to come down too, and eventually things will get to a "good enough" point where people hold on to their headsets for longer. I would say in 5 years it will be mainstream, but I think people are wrong in thinking this is something that needs to explode out of the gates this year. Acclimation is going to take time, the tech will only get better and more affordable, and by then there will be a ton of content because plenty of folks will be invested.
VCRs were like 2k when they first came out in the 70s, it wasn't until the mid 80s that the home video market exploded.