Steve can take a hike. He's blowing smoke.
Just the same, he's correct in certain ways. The party prefers public input that agrees with the party's approved candidates. It gives the public input, the same way bosses give a voice in meetings. You can say what you want, but the boss will have his way, no matter what. The boss prefers to get agreement in advance, but the decision is not conditional on agreement. The decision is independent of agreement.
When a party picks a candidate, the party is the boss, and the voters are the "workers." The party is usually successful in limiting viable candidates to those who are approved or acceptable to the party (party insiders), and in manipulating the process so one of a few selected, pre-approved candidates gets the nomination. This season, the winner of the nomination was supposed to be Jeb Bush, and may still be Jeb Bush.
But also this season, the party has a candidate that is both popular and unacceptable, Donald Trump. In Colorado, the party rejected the unacceptable candidate.
That all makes sense. Thanks. When all is said and done the vote is a formality; we have chosen, you either agree or disagree, it doesn’t matter. Maybe Steve honestly dislikes the system but he is firmly entrenched and won’t proactively do anything to change it.