It is almost by definition the agency problem. The hotel's agent has their own best interest in mind, rather than the hotel's, and can get co-opted by a small bribe.
1 - Pay employees a lot better, disallow tips, and make everything "All in" for the customers.
2 - Pay employees slightly better, and take all the discretion out of their jobs.
There is the ethical thing...and then there is what allows you to get a greater reward for intentionally forcing the cost of the reward on to a 3rd party.