Any holster will wear, and some finishes show faster then others. Ruger and springfield bluing seems like it's painted on, and thin at that. Some of the baked on finishes wear like , well, steel. Stainless just develops polished points where it rubs.
Leather holsters wear the least, and lined ones are the best of leather. Kydex wears quickly, and injection moulded holsters seem the worst as they are a softer plastic that tends to be subject to particles getting embedded in it.
my 2 cents on holsters.
IPSC style comp holsters have virtually no contact on the gun, so wear all but not at all.
If you want to keep it pretty, don't shoot it from a holster. If your gonna compete, look at holster wear like proof that your learning something. A guy with a shiny wear free gun hasn't practiced enough. In the end, if your competing with it, it's a tool. Take care of it, but don't baby it.