Earlier quoted context omitted.
Forget "useful" for a moment. How does good VR make you feel? Have you not had any "wow" moments? I'm constantly surprised how blown away people are when they try (real) VR for the first time. That's what makes me optimistic about it as a medium.
The problem I think, is how many people will actually pay that money to be "blown away" one time, and how many people will pay to be "blown away" multiple times after. We had few "VR experience center"s in our little city, they were popular when they just opened, but now most of it are closed. So, I think "blown away" is not enough, usefulness is important.
I'd prefer to use words along the lines of "inspring", "enchanting", "compelling" if we're going to discuss the potential of VR.
(I'm not belittling the large number of practical applications of VR in healthcare, training, education and content creation - but I don't think they will drive mainstream adoption in the way that creative, immersive applications could)