I have seen a ton of rude people at WDW. That being said, I am seeing tons of rude people everywhere. It seems that common curtesies and manners are slipping away.
I can't tell you how many people jump over or crawl under the gates in the ride lines when we have gone in the entrance and are making our way to the end of the line. I guess if no one was already walking to the end of line it wouldn't be a big deal but to do it and know that you are cutting others off is so rude.
Also, I can't tell you how many times my family has been waiting in line for a character and when its our turn someone else who wasn't even in the line just walks right up and cuts in. Most characters just give us and apologetic look and we wait our turn again. However, I have had some characters actually tell those people that they need to wait in line.
Yay for those characters!!
Character lines have been just crazy in my experience. Last time we went we waited in line for Lilo and Stitch, we were supposed to be first in line. We new they were coming back and so we waited there for about 20 minutes. As soon as they appeared my 2 year old were pushed away from the line, stepped on, and shoved. I couldn't believe it!! There was one woman that did most of the shoving. She was a woman all by herself. She did most of the stepping on and shoving all the while yelling "Lilo"!! and waving her autograph book. I wanted to die when I saw her the next day WORKING at the AK!!
She works at the place and still feels the need to push a 2 year old out of the way so she can be first in line to have her autograph book singed!! To this day I don't whether to laugh about it or be mad.
About the bus situation. I totally agree that waiting for the next bus is not always the answer. I have waited 45 minutes or more at times for a bus to arrive, so if you don't get on that one who knows when the next one will come. Sometimes the buses are right on schedule but NOT always. Then you must take into consideration how long you have already been in the line in the first place. With young kids sometimes you just need to get home/back to the hotel. If you've already been in the line for over an hour you are just desperate to get on.
We have waited before for the next bus. We have a large stroller and at times it was just easier to wait. However, just like the Lilo line, just because you are first in line for the next one it doesn't guarantee anything. We have had people shove and try to get on first anyway. We waited so that we wouldn't' hit anyone with the stroller. Which is hard to do on a very crowded bus. We also always wait to be the last off the bus so that we can get the stroller off without hitting anyone. We DO NOT have to do that but it is a curtesy to others.
It does irritate me when people don't offer their seats. It is probably one of the easiest ways for someone to show compassion for others, it doesn't take your time or money yet so many refuse to do it. NO they DON'T have to but come on, is it really that big of a deal to help someone out?!? I have stood with my DD at various ages on the bus, from infant to toddler and held her on my hip while I watch young children take up seats, who could just as easily sit on their parents laps, and teenagers who could offer the seat. I am not saying that they have to give up anything, but this simple common curtesy is so not hard to do. I didn't walk onto that bus expecting someone to have to get up but you can't help but believe that out of the 50 or more people sitting on the bus that someone will show you some kindness. If it doesn't happen then I stand, and go on with the vaction.
I have done it (given up my seat) for many people and will continue to do it for others. Its just the polite thing to do, and to top it off it makes me feel good to do something nice for someone else. Even if it is just a small thing like giving up a seat on a bus or in the waiting area of a resteraunt.
Last thing... about hitting others with the stroller. I am so guilty of this. People get very agitated with me. I ALWAYS apologize but in such a crowded place sometimes it just can't be avoided. I do my best to try and not nip someone's shoes but it happens sometimes. So, sorry to all I've hit. And next time your nipped try to understand that it probably wasn't intentional.
I do think having a child 2 and under sit on a lap to free a seat for someone who needs it is not a lot to ask. I can understand your concerns. I don't think my post in any way would suggest that you should put yourself or your family at risk. Sorry if you felt it did. 
