As I always say about US, same applies here if staff depend on tips – pay your staff properly! “service charge not included”, well you are paying them to do the job of serving, so WTF else am I paying for?
Go out of their way to provide good service, sure a tip is due.
A tip just for doing the job, no. That goes for taxis as well. I’ve paid them to drive me from A to B, why the hell should they get extra unless they went above and beyond just doing that task?
In US hotels, tipping for cleaning the room, again, that’s their job and they’re paid to do it. WTF should I pay extra? Of course if you don’t they might do a shitty job or steal something.
Japan has the right idea. They consider it an insult to be offered a tip.