I saw my 3rd busted escalator in my long life this year, so I don't think they're prone to fail. That one is in a dying mall they aren't investing money in any more.

I agree with Bert. It's about companies spending as little as possible to keep the doors open and money coming in. Clearly preventive maintenance is needed on these things, by skilled folks, and where you see all the failures is wherever they haven't been getting it.