The factory presets are designed to show off the capabilities of the kit, and tend to go for overkill.
Cancelling or merely tweaking just one or two of the chained effects can convert a confused noise into something usable.
For those of us without infinite time on our hands, it's a lot quicker to find a best-fit to the sound you're looking for and adjust it than to start from scratch, so don't knock 'em too hard. If you think these factory presets are bad, you should listen to the ones on the other famous unit that's roughly the same price.