I find this attitude very irritating actually, when staff do their job in a way that feels like they're doing you a favour. They might serve you with no attitude to make you feel happy to buy there instead of elsewhere, like asking for anything else feels like you're disturbing them.
I might be old school but people in any type of customer service should be approachable, pleasant to talk to, willing to help, and - in a single word - make you feel WELCOME. They should prefer to hire people like this, with a positive attitude to people. They are paid for this, to offer a service, not just to handle stuff.
I hate when I go to buy a coffee for example, and there's no warm human interaction. I also think that for people working there it makes your day better if you feel that your job makes customers happy.
In a hotel especially, when you walk into a reception, the first impression is fundamental. A warm welcome and the degree of service they are happy to offer make the difference between a cheap place and a five star hotel.
I think it's not fawning, it's being professional, and part of the profession in hospitality is offering a friendly welcoming, make your day special, a place to remember, and what you will mainly remember is not the beds or furniture but how you have been treated overall.
I'm sorry but I don't understand why it is so difficult to encourage your stuff to make clients feel that you are happy to see them, and do the work for them, you are there exactly for this. It's called hospitality business for a reason.
I think it's part of the training and it's not humiliation to make a client feel you're happy to serve them. I understand some might take advantage but there are ways to dismiss such clients.
Possibly you must have a love for people to work in hospitality, a certain type of personality.
Rather than reprimanding I would call it training your staff to offer the best unforgettable service in the business hospitality.