A couple of months ago, a friend an I went to a restaurant about 20 minutes before closing (8:38pm when we walked in the door, and apparently they closed at 9). We were exhausted after working at an event all day, and this was the first real chance we had had to get some warm food (outdoor event, raining, cold, etc). As we walked in, the waitress behind the counter was on the phone with someone who wanted to know if they could get take-out. She snapped that it was only 10 minutes before closing, so if they were going to pick it up, they would have to be on time, and she didn't know if the kitchen had enough time to complete their order.
The manager came out to seat us, and I asked if we had enough time to order. Of course, he assured us. We looked at the menu, and were still waiting for someone to come around for us to order when the waitress got off the phone and started venting loudly to another co-worker, "We close at 9 o'clock, not 9:15, not 9:05. 9 O'CLOCK". I just looked at my friend, thought a minute, then just told her sorry, that I couldn't eat there. We left our menus on the table, and walked out of the door. We were not the only people in the restaurant, either, and everyone saw us leave (because they were looking at the loud-mouthed waitress in horror, and we had to walk past her to get out).
We ended up at a restaurant across the street that also was closing at 9. The nice young waitress welcomed us when we came in, seated us immediately with menus and water, and we had prompt, friendly service, and the food was quick, hot, and amazing. We were out the door at 9:05 pm, having spent about $40 between us (we were starving! Nothing but cheese and crackers all day will do that!), and left a very nice tip (I think we left her about $10). We will be making a point to go back next year, and told everyone about the amazing food.
So yes, rudeness does affect more than the people immediately receiving it. I'd like to think that our leaving the first restaurant made an impression on that waitress, but she didn't seem like the type that would care, and would blame us if she did end up getting reprimanded or fired (this was not a younger woman who might have been clueless. This woman was about 50. Old enough to know better.).