You say
"most of the anime we see in the US", so who is we? Your (obviously limited) exposure to some
anime has spoiled the entire medium for you.
Anime is a medium, just like film is a medium, just like poems and photos and music and food and sculpture, to name a few, are all mediums. They are mediums for getting information or feelings or emotions across to whomever is hearing/smelling/tasting/touching/viewing them.
Your analogy of anime to rap is not a very good one. Rap is a style of music, it is a particular style belonging to a broader medium; just because someone doesn't like rap doesn't mean they hate music. The same applies to anime. There are many different styles and forms of anime, some are more prominent that others, some believe that anime ain't anime without tentacle rape others appreciate the more plot and character driven forms of anime. Some go for mecha action, others for light hearted humour.
Go watch Grave of the Fireflies or Princess Mononoke and tell me they are not as good as any other traditional movie you have seen. Or better yet, witness the spectacle that is Neon Genesis Evangelion and try not to get blown away. It drives me up the wall when people just dismiss anime as "just a cartoon". You say it isn't art, well then what is art then? If a drawing isn't art (and anime is fundamentally just a bunch of drawings) then what is?
So you had a bad experience, don't let it put you off the entire medium. Just because I disagree with one of your nodes doesn't mean I will disagree with all of them. The same goes for anime, just because you don't like some anime, that doesn't mean you should hate all anime.