For some reason I keep hoping that things will improve and it'll turn out to be a decent fic...and I get to the end of the fic and wonder how I could be so delusional...

I get the impression that it's fairly widespread. Of course, that's only from my bits of contact with the fandom at large. I think the Japanese see him differently as the non-Japanese which makes him more acceptable to them...of course, they create some of the most irritating female characters ever in their anime and love them, so there's probably something wrong with them...^_^;

I personally find Ryoma to be cute as well. Before I read the manga, I figured his personality would rub me the wrong way, but I was pleasantly surprised when I found I liked his snarkiness. I think it helps that I end up thinking of any deficiencies in his character as Nanjiroh's fault for being a jackass father...