Luxury hotels charge luxury rates.
In these rates, everything should be included.
Especially the salary of the staff.

It is completely disgusting to pay for every bag, for every waiter, or even for the concierge (sic!) additional money, to always finger around with dirty dollar notes!

When something really exceptional is done for you: Yes, than give a goodie.

But please don't teach the hotels to underpay their staff by paying additional money for standard service!

And please don't disgust normal guests who do not give tips for every standard by giving enormous tips for every standard.