It's not wearing out totally that I am concerned about, but enough wear until you have to index it to the next notch, when it's in between being too loose for one but really damn tight to the next, increased stress and wear on the threads, etc. Most systems use a detent such as a bearing or an arm claw that can move so this doesn't occur. Once the detents on the mount wear down, it won't mount as securely, and you will also be grinding away on the end cap of the can. One or both would eventually have to be replaced and that would be a hassle as opposed to a small part that can be replaced.
This may not be an issue for a long time depending on the materials so it may be acceptable, but it's not the best situation.
Wasted some posting space there going on about nothing but the foot in my mouth.