I'm 100% in on your point that in the highly cynical world and social media environment we live in, earnestness, sincerity and a sense of optimism have been devalued in a way they shouldn't be, and that there's great merit to storytelling that's earnest and sincere. Love that point, and I do love that about JRPGs.
But I'd argue that the immaturity criticism of JRPGs has more to do with the lack of subtlety with which the themes are repeatedly whacked over your head, not the fact that they're intrinsically earnest or sincere. It's the lack of brevity or editing in most cutscenes. It's the simplicity and "tropey-ness" of the characters and their sub-adolescent relationships, the hollow nature of most villains' motivations etc. The overlong pauses between a lot of dialogue to make sure children can follow along. To say the genre is written off by its critics because it is earnest and sincere doesn't quite hit the mark for me.
The thing is, it really doesn't need to be this way.
The best children's media doesn't treat its audience like children. It doesn't talk down to them or patronise them. It expects them to understand things, because children are actually very good at understanding things, it's not their intuition that is underdeveloped. They don't need fuckin monologue upon monologue.
There's a Zelda game that shares the same Big Theme as this game, and it does a much better job of conveying that theme. Even though the expected audience reaches even lower, the subject matter is handled with more subtlety and "maturity" (for want of a better word) than in any of the Xenoblade games.
It's also reminiscent of a children's book series which, again, treats its audience with respect and talks to them as equals.
Don't get me wrong, I think this game was actually a huge improvement in prior entries in this department, but that's why it was even more disappointing when it kept... Doing The Thing. You'd get really powerful, moving character moments, and then a bunch of fuckin Saturday morning cartoon clownery. It's weird. It's really really weird. And I feel like a lot of the audience have just gotten used to this stuff. And maybe I have too, and when I say it does it better than the previous games, it's just because I can't even recognise the stupidity anymore after having immersed myself in it for hundreds of hours.
Which is why, actually, I DON'T think that people who don't like JRPGs should just shut up. JRPGS becoming ever more niche, only palatable for a declining number of people who have become inured to all sorts of frankly bad nonsense is not beneficial for the genre. There should be aspirations greater than simply playing towards the base, especially when the base can be, uhhh, what it is.
I'm not saying they should become third person character action games, or that the only way to tell their stories is ape Hollywood, or anything like that. I'm saying that the, for lack of a better term, "anime" (which, I don't even know what that word really means, but trust it will work as shorthand) style shouldn't be
the only way to tell a JRPG story.
I think there's a lot to love about the strategic battle systems that these games have, that a much larger number of people might really enjoy, if they didn't come wrapped in a package of highly concentrated cringe.
Like, RE: Dunkey, the point that incredibly repetitive overworld/battle dialogue is annoying is low-hanging fruit, sure, but it's only low-hanging because if anything, it has only gotten worse in the ten plus years that Monolith has been making these games. Clearly long-time fans are not making the right complaints, so maybe that kind of outside feedback is valuable. Understand: I'm not saying it has no value or that nobody enjoys it, but I am saying that it's probably off-putting for a large enough amount of people that a simple option to just turn it off wouldn't go amiss.