I believe the problem of editing mangas on ocidental countries lies in the fact that the publishers are afraid that it would not be acepted, but sometimes they exagerate and publish a manga at a stupidly wrong price, that normal people who would bought it just for curiosity can't afford, so only fans would buy, and the manga sells less than expected, so tey don't put more mangas on selling because of that.
There is other problem, caused by the pre-concepts generated by the adults that don't have an open mind and think comics are just for kids so they're not worth read or worth buying.