Ah I'm with you there. Though I have used them, I can see the value in that. It hadn't crossed my mind. User presets make more sense to me than factory.
If I play the same guitar with the same mic and in the same room all the time. Or for those working with other musicians regularly, to set up and be ready, that's cool.
Then it's just adjusting to the mix. But that would be the normal process anyway I guess, balance the sound, clean it up, balance to a mix.
I don't tend to use factory presets for anything really. If there was a 'global fx off' option on a synth, I'd use that when running through patches, and is usually the first thing I turn of to actually hear the synth.