It's my opinion, so it's true!
I think the original tough guy Chinese boxers used to really fight and they developed a core body of techniques. These techniques exist in all styles today.
But they got to start hanging out - one of them strings a couple of their sequences together and the others thought, "man that's cool". So not to be one-upped, they strung together a more complex sequence to use to showoff with and added a little flair. Over time, these sequences took on a new unintended meaning. Eventually the dancing, flair, and showing off started to replace the fighting as a means to display real skill. People started to attribute too much to them and started inventing all kinds of terms and mysticism to associate with them like fa-jing, yi, li and really believed that forms meant skill.
It's true that a couple of forms are good for creating a base in an uncoordinated and out of shape individual, they aren't good for teaching fighting because they were never intended for that.
They were intended to be much like this: