It's amazing how many people will agree with that statement (because... duh) and then freak out when someone points out it's impossible to talk about the DSM without talking about dominant beliefs regarding "what society should be like". I.e., without talking about politics and labor economics.
There are many topics covered by the DSM that are maladaptations to this society but a) would not have been maladaptations in previous soecieties, and b) might not be maladaptations in future societies.
Is it even possible to talk about something like whether some particular aspect of human sexuality is a disorder using only "real science", and on a related note, what does "real science" mean here? E.g., there have certainly existed human societies with no strong taboo around human nakedness, and in those societies Exhibitionistic Disorder wouldn't even make any sense to talk about.
Similarly, it'd hard to imagine ADD being anything other than a perfectly normal non-maladaptive variation in personality prior to industrialization.
As a practicing scientist, I'm honestly not sure how "real science" is supposed to given an answer a question like 'is being transexual maladaptive?" It's just not a scientific question. There are lots of related scientific questions about human biology. But ultimately, it's a question about how those biological facts interact with social constructions.
Can you tell me, concretely, what you mean by "real science" here?