Interesting re Lawers. I can’t imagine that folk are riding off trail as there really is no benefit to doing it. If folk haven’t the right kit, that is their look out. There will always be folk out on the hills like that no matter which group they belong to. No need nor excuse for rudeness though!
What are they ripping up higher up? The path is so well trodden, I’d struggle to see how. Are folk heading off trail onto the grass?
As for Ben More, I have walked it from the south. I would do that but when returning via Stob Binean, I would head east onto the lower top to descend down. There is a nice section of singletrack on the lower top but the path then disappears. The Stob Binnean path is guff as it is too steeply eroded meaning that you have to stick to the grass.