No one else is replying to that because no one else has that problem, I know I don't. Are you sure there isn't any dirt getting under there and causing the scratching? I take mine off once or twice an week and clean the phone and the case and have no issues.
I clean mine at least 1-2 a week, so there shouldn't be a problem. The way I take off my Magpul, however, is from the top corners. I'm a petite lady with pretty small hands. Sometimes, the material is tough to take off. Should I be removing the case from the side instead? I didn't have this problem with an NGP case, but that material was less stiff in my opinion.