After 6 months there was blood everywhere..
Twitter’s Bootstrap is not complete either. Without a vision like YUI’s, you cannot go far! Though, if you have too many ideas in your head you can not have a stable library either; there are still many “beta” components in YUI.
Maybe we should have paid for a product like ExtJS. They took YUI to the next level.
I’m afraid of becoming an advocate for using frameworks! If you don’t know what you are doing, just use a framework; not all of them are for novices though..