I do kind of agree with you. I think the DNC is biased in favor of Clinton, and not in a conspiracy way, but in the small subtle ways that's not obvious if it actually has an effect on this election or not. I don't think it does, but I can't think of a way to prove to disprove it.
In this particular case though I find it hard to take the Sanders delegates complaints about how undemocratic and unfair this was seriously because I think all caucuses are undemocratic and unfair, and I think this particular Nevada caucus was undemocratic and unfair, and I think the follow up convention where Sanders supporters netted more delegates for Bernie even though he lost Nevada was undemocratic and unfair too.
And so, when Bernie supporters point and complain at how the voice vote was undemocratic and unfair, well, that ship has already sailed. If we're interested in making the Nevada caucus vote fair, it's kind of too late.