I‘l answer for myself, and others can say why they do or don’t like skiing them.
For me, first of all, It’s not that I don’t like skiing groomers at all, it’s just that I like other things much more.
Here are my reasons, not in particular order:
I love deep powder. Who doesn’t? Anytime you see snow, people on foot are going out of their way to walk in it, kick up clouds of it, stomp in it, there is just somehting about deep untouched snow that humans (and dogs) can’t resist!
I like more rugged, natural and interesting terrain. Visually for one thing.
I like mountain biking much more than road biking too. Same thing.
When I stand on top of a groomer, it's immediately obvious that I will get to the bottom, and there isn’t anything to figure out. I prefer the ‘puzzle’ of looking at the terrain, and figuring out how and where to get down.
I love the floating feeling of powder
I love the feeling of up and down, fast and slow that you get in moguls
I don’t like that there are other people blasting by at warp speed (although having someone come straight at you as you are both curving around a tree from opposite directions, is even worse))
On a cold day on a easier groomer, I get cold: high speed= wind+little effort