Like Nachria, I, too, have noticed a significant difference in the behavior/attitude between lobby staff and the rest of hotel staff in the hotel where I live, and at other hotels on the OP list which I have visited.
Why is this?

One would think, at top hotels, with top training resources, that staff behavior would be consistent across all their departments.
But several posts here, including mine, agree that lobby staff seem to be an exception.
Can anybody offer any clues as to why?
Hopefully, those clues will help travelers select the best hotels.

-- Peter