Some people are hating this show because they either hate DC or they don't know that it's an origin story, characters don't look like the one's in the comics "yet", because they haven't become 'starfire', 'raven', and 'beast boy' yet.
It isn't a cartoon show which needs no detailed introduction of a character, it's a TV show adaptaion which always needs a good introduction, and this did a great job in introducing the characters in the first episode.