I'm sure they can't be there to 'save water', as they auto flush as soon as you stand up, knowing good and well you still gotta wipe your ass and flush again anyways...
That indeed is understandable as well. In my area, almost all public toilets have the auto-flush feature though.
The problem isn't that it's a thing, it's more like it's ignorantly engineered. It'll auto-flush just as soon as you get up, or even so much as reach for toilet paper, even though everyone knows people need a moment to wipe...
So like, why not have a minute delay or so on the auto-flush feature?...