It's up to you if you think ecchi or hentai is gross, but....
Errrrrrrr.. did you read yaoi as well? Yaoi, esp the smutty one, is also just porn. And it is originally just simply gay porn, contains only smutty part, that is why it is called YAma nashi, Ochi nashi, Imi nashi: "No peak (climax), no fall (punch line), no meaning".
And manga is a type of comic created in Japan or in Japanese language. So, whatever the drawing, the art, or the story, if it fulfills the Japanese comic format, it can be called a manga. And among those, we have hentai (hetero porn manga), ecchi (softer version of hentai), yaoi (gay porn targeted to women), bara (gay porn targeted to men).
This just porn why still name it manga
Fucking gross
Do get me wrong i do like porn but this is just ..... bluh