We are currently at the moment where every aerospace manufacturer in the world is building some kind of autonomous sky taxi... seems like every idea has its time and specific technical requirements.
If they're proposing an ultralight, I'm not too skeptical. Loads of companies have successfully created ultralights. If however they're trying to sell me the dream, like Moller, then more skepticism is warranted. There are a lot of problems with the dream that aren't really problems for limited production ultralights. For instance, the simple matter of how much low air traffic is tolerable to the community. Or the incidence rate of poorly maintained aircraft falling out of the sky and crashing through my living room ceiling.
If these MOF people were talking about more efficient desiccant dehumidification, I wouldn't be nearly so skeptical. But by making it about the noble feel-good mission of drinking water from thin air, they're sending out a different sort of signal. It tells me they're looking for hype, and the way they're doing it has a past association with scams that I can't rightly ignore.