unfortunately, most people don't conduct their lives in a "customer service" type mindset. that is, they don't walk around thinking about how they can make other people's lives easier, or anything like that. this especially sucks for people who are in a customer service position (such as hotel staff), since it's formally their responsibility to be all nice and helpful. the customer then gets into a "give an inch, take a mile" type of thing, etc.
punchline: expect to be walked all over, appreciate the occasional nice person who realizes that it's in everyone's best interests to be mutually supportive.
ps
when travelling, people often are edgy. that may contribute to them being curt, impatient, demanding, etc.