If the aesthetics and continuity don't matter, why have any visual continuity at all? Why not just say we should treat this like The Simpsons or a James Bond film where what happens from story to story doesn't necessarily carryover and each is a story about "exploration, struggle and human growth and development, optimism in the face of adversity" if that's all that matters?Except Trek's identity is not the aesthetic, but the attitude of exploration, struggle and human growth and development, optimism in the face of adversity.
If it's all about that for any story at a given point, and not how the story fits within the larger continuity of Star Trek and how it connects to that history, then going The Simpsons route wouldn't be a big deal. But what some fans have argued is that it is distracting when the producers want it both ways. They want to use the history of Star Trek by filling a story with Easter Eggs, but then are like "why are you so bothered?" when those Easter Eggs are inserted into an episode with elements that don't fit together well with established continuity.
Then you would be no different than a lot of fans who dismissed TMP for 20 years, before reassessments started shifting people's minds about it, since it was considered one of the "bad" ones that was made before they figured out how to get things right with Wrath of Khan.Neither did TMP. And I'm sorry it still doesn't.
So I shall reject TMP as Trek as well.
I would also argue there's something fundamentally different between TMP and Discovery. TMP was a continuation of TOS set years later. A central theme of the story is change and growth, with the characters (and Enterprise) having gone through changes (e.g., Kirk not able to let go of the Enterprise after becoming an Admiral, Spock trying and failing to let go of his emotions, etc.). Discovery, on the other hand, is a series inserted in-between specific, established continuity that introduced new elements that didn't fit with that continuity and basically said it is what it is.