I have, and I have several problems with them:

1. They're the tightest of trousers. I still get along well in fairly baggy pants (not sagging, mind you) but jeans can get quite uncomfortable.

2. The pockets. Utterly unusable. If you're like me and don't use the back pocket (pickpockets and sitting on your wallet = not so good) then that leaves the front ones. Try sitting down with a jeans pocket with a wallet in it. Ouch!

3. The price. Kilts are expensive, but for the most part they're hand made from a lot of material. Jeans are machine made by God knows who - and most of the time they're pre-worn for you.

I do sometimes wear a flannel-lined set from LL Bean, and that can be pretty comfy, since they're looser. But jean-cut pockets are awful, and I certainly wouldn't have bought them for myself (clothes got mixed around a lot at home when I was a kid).