As long as it has a compelling story it's legit anime. The moment it becomes straight out perving with no real storyline (wholly sex driven plots do not count as plot)...then it becomes porn.
Well written Ecchi tends to have some of the best comedy of any anime so it definitely should not be discarded.
I think it just depends on a person-to-person basis. some people aren't gonna be big fans of hentai and that's fair. some people will only like hentai because of the sex stuff, which is also fair. some people want to watch it for the story and everything else is just a bonus.