There definitely is a bit of chicken-egg going on. But at the same time, if there was a truly emerging market, people would find a way to try and force it.
Right now the main issue is that there aren't even really great, cheap ways to mass produce them. Almost everything that's been performed on MOFs has been at the laboratory scale, and there's not necessarily a clear path to scale up. And there are fundamental cost-to-effect ratio issues that can't necessarily be easily overcome.