Honestly, mate, I find them to be, largely, an unscrupulous lot....

Honestly, mate, I find them to be, largely, an unscrupulous lot. There are some who seem fairly balanced and just have a more pragmatic approach to what the company is doing and rightly point out some of the failings. You can tell when it's rubbish, they'll repeat it ad nauseam.... But it's still draining. You need to put it all into perspective.

Does the tech work - seems to
Is it financially viable - seems to be
Will they have financial capacity to start - seems likely
Will there be a market for their product - definitely
Is it taking longer than they claimed - yes (does it matter?)
Do they have the right people to make this work - I think so

You make your investment decisions, not them. It's pretty lame to blame them for your loss.

Hang around, you might get another chance to get back in.