When I travel, I have often hear common comments from hotel staff (that I get to know) about their views on people they serve.
Here are a few, to stimulate discussion:

Many German travellers do not wait in cues like other travellers and are very demending and often rude ro servers.

Many US travellers (especially Texans) often are demanding and many tend to be on the "braggy" side....though some they tip very well.

Some British travellers can be loud (especially those from Manchester and Liverpool) areas....do they ever sleep? They also seem surprised that economy hotels do not give 5 star service.

Many Canadian travellers are far too nice (being on the edge of shy)....except the French Quebecers.....who travell in "packs" and expect that all servers speak French....even where French speaking customers are a small part of the clientel.