They want to, it's their vehicle :dunno:
Most of the ones I have seen are the "don't want to cut the sheetmetal so lift it to the sky" type anyways, so you could put them back to stock by undoing the idiotic suspension modifications. I view it the same as say, putting 38 inch tires on a family station wagon, just a heck of a lot less functional.
What I don't really get is "slammed" rides that are so low you can't pull into a parking lot, with the tires sticking through the wheel wells and the rocker panels chopped off. It's like the worst of all worlds, you get no ground clearance, no cargo capacity, can only drive on flat surfaces... nearly as bad as a multiple-foot poser lift with a horrible center of gravity, no suspension articulation, terrible steering, etc.
I don't like mods done only for looks with no thought as to how they effect functionality - I like functionality a lot. That's not to say I don't care how stuff looks as long as it works, I just prefer functionality if I can only choose one or the other.