I guess there's several use cases and potential customers that they need to keep in mind when creating pre-sets. Some people will play into a clean tube amp, some will play into a solid state amp, some will use with single coils some with HB's. Then there are people who will exclusively use this hooked up to a PC, some will use through studio monitors others through headphones. Then there's the varying quality of gear being connected to.

Then they need to consider who plays the unit, younger guitarists will be impressed by crazy effects, their abilities may be somewhat limited so the sound of a heavily modulated flanger with tons of gain while playing a power chord may float their boat. Then there's older more experienced players who are looking for something more subtle.

I'm not making excuses here and I think most manufacturers pre-sets suck but I guess it's not that easy to make good sounding presets that will work well for everyone out there.