What are the market pressures against Virtual reality Movies being a thing?

Well, first there's the fact that the consumer pool is small and likely to continue being small. There are only a few million potential customers out there right now, and they don't all belong to the same demographic. You can't even assume that they all have the same tolerances that would be needed for a VR movie. So, realistically, you're targeting a few hundred thousand people. They'd never produce a conventional film with that kind of narrow appeal.

Second is the fact that you need to invest in radically different equipment to make a VR film unless you only focus on computer animation. A high startup cost for the studio and a low anticipated return? We're not exactly looking at an accountant's dream here.

Finally, though this isn't really a market pressure, the fact is that the VR movies that do exist have generally failed to justify why they exist to audiences. No one really knows how to direct a film where you can't make cuts, frame a shot, or even use conventional lighting rigs and still make it compelling. Those who try to mix things up oftentimes just end up making their viewers vomit.

And the idea of experiencing a passive narrative through VR, where the medium is based entirely on trying to make you feel like an active participant in what you see, is almost antithetical. This is why so far most directors have stuck to shorter projects so they can more freely experiment with what a VR film would actually need to be. Until one of those demonstrates that it can get audiences engaged enough to go through a whole movie, there's very little incentive for movie studios to risk investing in any VR projects.