Don't underestimate the value of your own time. You could keep working for a floundering startup... or you could sue for lost wages... or you could move on. I'd guess that there's more value in politely quitting and trying something new.
You are right, there are so many fascinating ideas and start-ups are getting built around them. Why stay on the sinking boat then...
Exactly. Beware the sunk-cost fallacy! If you weren't already at this company, then would you join it as an unpaid developer? Many other opportunities are out there. Do something that excites you.
One thing I didn't consider but should have already this morning. I would not join it at this stage even in my worst dream. So there is really no reason to continue for me... I'm done