So the thing about "Ya'll should ..." is that it's often mistaking "Group A and Group B hold conflicting beliefs but share a characteristic" with "Group C, all the people with this characteristic, all exhibit an incoherent belief structure".

For example suppose you apply this to the US Senate. So instead of Group A (Democrats and a those who caucus with them) and Group B (Republicans) we instead think there's a single Group C, Senators. Now their behaviour seems incoherent, this Group C seems to hold contradictory opinions and behaves irrationally, why can't they get their act together? The actual answer is that we misunderstood and they're not a single coherent group so that's why they don't act that way.

You might as well argue: "Part of my brain thought A at time Y. A different part of my brain had a different thought B, at a different time Z. Why the accusations of hypocrisy?"

The problem arises when an individual or group tries to represent themselves as more credible/consistent/coherent than they really are.

If you freely admit that you have multiple personality disorder, hypocrisy is to be expected from you as an individual. People know what they're in for.

If you respond to accusations of hypocrisy by saying: "Hm, that's a good point. I'll have to reflect and see if I can reach consistency here." Then people recognize you are making a good-faith effort.

I've observed that modern progressivism represents itself with a strong us/them boundary. The vociferousness of the rhetoric vastly outstrips the quality of the underlying reasoning/decision mechanism. And I've never seen a progressive say: "You make a good point, we'll have to debate on that."

You are correct that individual progressives may, in principle, be credible if they have a coherent philosophy which is consistently applied (including to critique their own "team" when appropriate).

But empirically, modern progressivism is more of a "meme ideology" where precepts are invoked when convenient, against whatever outgroup is currently fashionable. Progressive rhetoric, and progressive reasoning, is so flexible and untethered that if you're sufficiently talented at wielding it, it can be used to reach virtually any conclusion. The selective application of principles at the group level has strong parallels to how hypocrisy works at the level of an individual.

A movement can be meaningfully described as hypocritical, even if its individual members are not.