I would totally disagree with your remark about having a juvenile approach, at least when it comes to what I consider to be his best scripts/films. Movies like True Romance, Reservoir Dogs, Pulp Fiction, Django Unchained and Inglorious Bastards had great dialogue and story lines in them. Some of the best scenes in movie making history come from those movies in my opinion.
Tarantino has a very juvenile approach to film making in my opinion. It's as if his target audience is fifteen year old boys. Also, along those same lines it's as though he makes films for the sole purpose of seeing what he can get away with and sometimes how gratuitous he can be. I can almost hear him saying to himself things like "this is going to be cool. Nobody is going to see this coming." I just don't see how his film making ability and style would translate well to a Star Trek movie.