Sadly it's what many people think, that's why I don't really tell a lot of people I watch anime, (especially how much lol). It's not really accepted where I'm from.
But I always think when I hear people say that it's for little kids, that most the animê i've seen I wouldn't want kids to see. I think there are mais serious animes out there than not.... or at least I guess those are the ones I stick to. No.6, Wolfs Rain, Another, Code Geass, and Psychic Detective Yakumo are just a few of those animes that take there audience very seriously.
To be honest I've never actually heard anyone say that...
But some shows are for kids and if someone wanted to think that, it's fine it wouldn't really bother me. If they're saying something like that they probably don't watch much animê anyways so it doesn't really matter.
those people literally don't know anything. It's like saying "oh it's a comedy movie Adam Sandler is definitely starring in it." Like typically the only animê I can think of that's purely for kids is Pokemon.
When ever someone says animê is for kids I look at them and say..Can animê make you cry..does animê have porn..does animê has romance..does animê cuss..does animê scare people, yes it does and Im sitting here like now you know :L