The assumption in that statement is that the trail being convenient for people is the only important consideration.
I was out hiking a couple of years ago on a very steep trail with lots of signs telling people to stay on the trail because they were trying to regrow the forest in the surrounding area to prevent land slides... and what did people do? They cut through it anyway. No wonder they had to shutdown entire portions of the trail.
Sometimes things have to be done a certain way for other reasons. The most convenient technical solution is not always the right solution either.
The assumption? I think it is more subtle than that. Your example shows that if perhaps there were two trails, say the one for the hasty short-cutters, and one for the others, the inevitable damage could have been minimized and a closure avoided.
But my comment wasn't about trail management, I'm recounting an anecdote from 25 years ago. The point was to check your assumptions against reality, and adjust accordingly.
I wish more trails I walked had "fast, hard, short" vs "slow, easy, long, pretty" route markers - and not necessarily in that combination! Sometimes a long trail is long because it's pretty, sometimes because it has low grade. I've walked with people in crutches and wheelchairs, warnings that "this trail has steps" have been invaluable (and really annoying when missed).
I might not totally understand the context of the trail you were on, but how does making the trail less convenient support re-growing the forest? It seems like the regrowth probably has little to no preference on where it occurs, so couldn't the trail designers still have made the trail with convenience as the chief goal?
I was out hiking a couple of years ago on a very steep trail with lots of signs telling people to stay on the trail because they were trying to regrow the forest in the surrounding area to prevent land slides... and what did people do? They cut through it anyway. No wonder they had to shutdown entire portions of the trail.
Sometimes things have to be done a certain way for other reasons. The most convenient technical solution is not always the right solution either.