I'm not "making excuses", but I think the US service industry management puts un(der)trained personnel to deal with the public way too soon, and management in many cases do not treat the employees with the proper respect, etc. On the flip side, I think that many US service employees don't treat their jobs like a career, but rather, just as a job until the next one, and as far as younger people go, many aren't all that well-educated, and have been raised in an "its all about me me me" society.
I always find it a pleasure when travelling to places where service is great, such as in Chile, where I frequent. Almost every hotel, restaurant, cafe, airline, rental car, etc. transaction is pleasant, if not a pleasure. I'm talking about ranges from a $3 lunch to a good restaurant, from a $30 hotel to a $200 hotel, from a 45 minute flight in economy to an international F flight, etc. (Of course there are exceptions, and I have a few stories...)
My european experiences are similar, but lesser. My limited Asia experiences have been generally very good.
Although I don't know for sure, I think in most other areas, the service jobs are viewed as a career, and if you don't have the disposition to deal with the public, you shouldn't. In the US, a lot of service jobs are filled with space-filler, and if the hotel stays relatively full, it doesn't matter who is at the front desk.
I can't speak for the rest of the world, but long-time service workers in the US are facing unprecedented cuts in wages, benefits, workrules, and so on. It has to be a serious drain on the morale - all while now having to work with incompetent, inexperienced, unmotivated young coworkers. (Again, there are exceptions.) I don't know how some of these people still can have a smile on their faces, but many still do. I also find that a service worker in the US is going to generally get less respect overall from customers, and eventually, even the best may snap from time to time. It doesn't make it right when I'm the one snapped at, but after being spit on all day, I can see why it can happen.
Its funny that as I write this, I recall my fish purchase of earlier this week - I usually go to a very small store in Berkeley, with owners of Japanese descent, who are always so polite and grateful that you are buying their fish, I even received a bow from behind the counter of the fishmonger - both as a welcome, and after I took my piece of fish.
Ok, I'll stop now, but this is an interesting topic that I may have more comment on later