1.a) Sure. It is a big leap. But guys who become gun-shy of this kind of thing tend to see it everywhere.
1.b) CGuy didn't make any sweeping assumptions about anything. MY sweeping assumptions were about what was going on in CGuy's mind. What kind of person she is or isn't, I couldn't say. I haven't bothered to read whatever it was that CGuy read. In your parlance of memes: Look at all the fucks I give (feel free to imagine your choice of: spiderman, stephen fry, or Maria spinning in the foothills of Austria, etc...).
2) RE: sweeping generalizations and your inability to understand them.
Humans are good at filling in gaps based on limited information. It is one of our most effective survival mechanisms and we do it all the time. ALL THE TIME. Generalizations have a bad connotation with some people, but they are inevitable, and indeed quite useful most of the time.
The only real problem with making generalizations is when people refuse to ignore evidence to the contrary. Here, we have no evidence to the contrary. Hence the words MAY and MIGHT appear throughout my post of complete guesswork - guesswork not about her, but about CincinnatiGuy and what he MAY think about what her statements MIGHT indicate.
The funniest part is that my guesses are way more reasonable than his actual reason seems to be: I don't want to take another shower. Because showers are unpleasant and tiresome? Maybe he wears a piece?
However, I would guess that you are also high-maintenance based on how long it takes you to get ready (2+ hours, in spite of the 1 minute it takes you to wash your hair). You are sensitive to this label because you know that it carries some pejorative weight and you resist what you see as the wholesale compression of your complex personality into such a limited space with a largely negative categorization.
But only an idiot thinks they can really KNOW what kind of person you are based on some words on a screen, some pictures, and some of your stated preferences. But such is life on the interwebs. The necessary chemistry of real-life is removed from the equation and often times people forget that pictures aren't very good representations of how a person really looks, words on a screen are divorced from tone and wholly susceptible to prejudices, and that anyone of sufficient intelligence is far too complex to really ever understand completely, and certainly not meeting them half-way.
So... we fill in the gaps.
3) It wouldn't be her honesty that would have indicated anything. It would be her attitude. Her honesty is no more laudable than the girls who state a preference for incall or outcall, or a preference for the color of clients' skins.
Giving her props for her honesty seems bizarre. Honesty doesn't cost her anything and in fact is probably better for her. Why would she lie? Most guys wouldn't care and this instance, with this ONE dude - Cincinnatiguy - is probably the only instance where it has ever come up.
I would say that if she's going to react strongly to it, she actually has a greater than average motivation to explicitly state her preference. It's just self-interest and, in this context, neither worthy of praise nor of snarling derision. Her "honesty", in and of itself, is neither. As you say: BFD.
TL;DR:
meh...