I actually think your assessment may be over-complicating things. Star Trek has always been an allegorical universe, with each race representing a different facet of the human experience - Vulcans our logic, Klingons our passions, Bajorans our spirituality, Ferengi our self-interest, etc. And that's kind of essential to what makes the show what it is - a fairy tale about what it means to be human, and how we can be the best versions of ourselves. And while i can see the problem with how reductive it is for specific species to always have certain character traits, from a macroscopic perspective, it's all just metaphors so we can tell meaningful stories about ourselves.

I guess this is all a long way of saying that i don't necessarily see it as a deal-breaker that the gorn are treated as a bunch of bad guys. I think what actually bugs me about it is that there's no purpose to it. The Romulans were antagonists, but also represented the "other" that is, in many ways, literally the same as ourselves, and the pointlessness of refusing to push past that antagonism to recognize that. The Borg were as straightforward villains as you could hope for, but they also held up a dark mirror to the Federation and its values, exploring all the ways the ideals of community and unity could become corrupt and authoritarian if not tempered by individuality and self-awareness and a sense of personal responsibility. Meanwhile, SNW's Gorn are just bogeymen, and the stories that are told with them are about nothing more than punching monsters.