The "characters" in Jar Jar Abrams Trek are loud, crudely drawn sketches for an audience that is barely paying attention, that's why they're crappy.
There's nothing wrong with selfish characters or unsympathetic ones. I like characters because they're interesting, not because I'd like to have a beer with them. Harry Kim seems like a really nice guy but he's dull and lifeless. Would rather watch an interesting selfish character like Quark.