I don't think we can generalize about broad categories of "purists" versus "revisionists," but I do agree that classic Trek definitely had a utopian backdrop, a very optimistic vision of humanity's future... and optimistic futurism is out of fashion these days, whilst dystopias are very much in. A lot of people seem to want to inject more of that into Trek, for various reasons, and it doesn't really fit. (Especially in a prequel series.) I can enjoy a different SF show like The Expanse or Dark Matter on its own dystopian merits, but I don't want too much of that sensibility to infect Trek.
(For those of you who are comics fans, it's worth mentioning that similar debates have gone on for years about the future occupied by the Legion of Super-Heroes. It's always been optimistic, but just how utopian should it be, and how dark should any given story be allowed to get without "breaking" the concept? I personally very much enjoyed the 5YL Legion, for instance, but largely because it was a carefully conceived thematic contrast to what had come before, and acknowledged the virtues of trying to rebuild what had been lost.)
(For those of you who are comics fans, it's worth mentioning that similar debates have gone on for years about the future occupied by the Legion of Super-Heroes. It's always been optimistic, but just how utopian should it be, and how dark should any given story be allowed to get without "breaking" the concept? I personally very much enjoyed the 5YL Legion, for instance, but largely because it was a carefully conceived thematic contrast to what had come before, and acknowledged the virtues of trying to rebuild what had been lost.)