One Direction actually have some really great songs, and talent. They are more than just their early hits and "boy band" image. I used to dismiss them too but then some friends of mine (we're all in our mid-twenties) got me into their stuff and I have to say it has some substance.
If people only judged the Beatles based on "She Loves You" and the Beatlemania phase, they would be considered a boy band too. Maybe try giving a listen to some of One Direction's more recent album tracks and you will see they are more than just good looks. Also, I don't see why having a teen girl fan base is a bad thing. The Beatles' biggest fans were always teen girls. They wouldn't have been able to become global sensations and take over the world (which allowed them to experiment with more daring music styles later on) if it hadn't been for the teen girls who made them millionaires. One Direction has a lot of female fans, that doesn't invalidate them as musicians any more than it invalidates the Beatles.
That being said, I think One Direction have more in common with the Monkees than the Beatles, because like the Monkees, they were conceived as part of a TV show, and weren't given complete creative control in the beginning, but later began to experiment with songwriting and musicianship.