I have,
even from the actors themselves.
There wasn’t enough drama. It just wasn’t a Star Trek movie. We had the Star Trek people, but it didn’t use us as Star Trek characters very well.
Kirk and Spock were both, in their own way, directed to act in an unsympathetic way. Kirk undercuts Decker and just nastily barks orders to everyone. Spock is colder than he ever was in TOS. Yes, that was integral to the theme that led to Spock's epiphany in Sickbay, but it was NOT the kind of reunion fans wanted to see, and it's still kind of a tough pill to swallow.
(Actually, the audience subversion of character portrayals kind of reminds me of The Last Jedi, ya know, Luke throwing the lightsaber over his shoulder, etc... I just don't think TMP intentionally screwed with expectations. I think the filmmakers were unaware and/or unconcerned at the time of what those expectations were.)
I know he petitioned Paramount to not recast, but I just don't get the sense Gene was sentimental about the characters in the sense of the nuances of their portrayals and how they best interacted. He saw them primarily as a vessel in which to deliver the
big-idea message. And this, IMHO, relates to how he approached The Cage. Storytelling was mostly about conveying an idea, not following character arcs.
Of course, I'm sure some will continue to find reason to disagree. But I've pretty much said my piece and I'll just repeat myself at this point.