About the waste of water; that is trivial to the concerns of the bathroom owners and operators. The problem is too many people don’t flush in public bathrooms. They don’t think they need to, because at home they don’t if they just pee, or they don’t want to touch the toilet handle to flush, or they use their foot to flush and risk breaking the toilet. Not flushing means the toilets get clogged more, so the more flushing the less likely there will be a clog and the less maintainence. If all people used the toilets like civilized people (this is similar to my rant on a different Q about people not hanging up clothes in a dressing room and not cleaning up their table in fast food restaurants; I am on a rant) they would not need the automatic flush toilets. Auto sinks mean sinks are not left running, which I have seen too many times in public bathrooms.
Another good thing about automatic everything is less likely to communicate colds, flu, and other illness. Although, it is more important at the point of washing your hands and the door to get out of the bathroom.
The toilets can be adjusted, some of them are too sensitive and flush too much, I agree with that. Basically what @Mariah said. Wiping the seat and puttingndown a seat protector can trigger it, and then if the flush is too strong the water sprays out onto the seat. So frustrating.