Personally, I don't say please much, however almost always say thanks. It's part of my profession where lots of orders are given so that sometimes carries over to other parts of life, but once the task is done, I'm good about saying thanks....

I suspect that many biz fliers are also in the same boat where lots of decisions are made and that practical curtness carries over since lots of the travel is related to biz....

Not that please may and thanks couldn't be added in but the cultures of some biz environments foster this....