Why are almost all boys' fanfictions either smut or shipping fics?

Like, don't get me wrong, I love shipping just like everyone else, but why is that the only content there is? Aside from a few, there are no fanfics that focus on plot (and a lot of them are out of date). (For clarification, I am currently trying to write some of my own but I'm not that good at writing so I don't know if I'll ever publish them.)