I found mountain running a challenge to think about when it became really popular a few years ago. I think that was because for a while it wasn't well established, that highlights were often people who'd almost never visited remote areas suddenly running through them, and yet it's difficult to functionally distinguish it from tramping because in many respects it's just tramping with less stuff.
For something like mountaineering it's much easier to tell the difference from tramping. They occur in distinctly different environments and involve different skills. There's an easier distinction. ie. If you choose to do this, which is in a different place and with different skills, then these are the risks and that's the best practice way of doing it.
Mountain running and tramping are harder to distinguish, though. For decades trampers have been visiting these places and figuring out best practices, largely through experience, deciding what's "right" and "wrong" especially when it comes to deciding if people deserve criticism when something goes wrong.
Then suddenly a wave of different people come through. They visited the same places over the same distances but with what seemed like different best practices Faster, lighter, but arguably the same hazards that can cause things to go wrong, so seeming to take different levels of risk. Especially with PLBs becoming popular at the same time, it arguably meant using someone else to compensate for increased risk. That messes with what were some established perceptions for trampers of when it's okay to be critical of others and when it isn't.
I think I'm over it now, though. It's been going long enough that I can appreciate there's a well established community that has its own best practices for things like safety. When they're followed they look alright, and some of them are leaking into tramping best practices, too. It helps even more that there's now more crossover between mountain running and tramping communities, including in some clubs, and so people are actually talking to each other.