Finally, real market cap GNO equalled REP - similar project, also without working product, but with high promises. So, wisdom of crowd exist, LOL!
Buterin warned about this possibility and proposed to start auction from incredible high prices, to stretch it in time, i don't know, why nobody listened
In general, I liked answer of MakerDAO's developer on Reddit (it's @kennyrowe, he's here too) on question, what happened with Tether peg:
Pegs are only as good as people think they are. If (for whatever reason) people don't think the peg is or will work, then it doesn't. This is why they are so difficult to maintain, because people are fickle things that change their minds often and for unclear reasons.

What happened to Tether? It was a peg and pegs break.