I really won't blame them, because nobody would want to see their money waste or reduce in value like that. I once invested $1000 in a project back in 2018 and till now my money is not even worth up to $100. Nobody is willing to wait that long to get ROI.
That's huge, if you do experienced that kind of losses probably you'll be seeing the other side of this investment, you have to double check if there's really something that still progressive from the developing team, but if there's nothing, you have to move forward.
It's about taking your chance and if you can deal with decent profits in a much quicker term it's much better than losing it in the long run.