A:A number of reasons it could be. 1. Being inconsiderate, they don't want anyone next to them and refuse to give you an inch of space to take the seat..2. If they are polite and let you into the seat next to them, they likely plan to get off at one of the next few stations, so they don't want to have to climb over people, if they don't have to.  Chinese people can be very inconsiderate, but also shy and don't like to say "excuse me" or "mmm goi" if they can help it.3. The bus gets very crowded, so if it is full of people standing, not only is it a PITA to have to get off the bus by being in the window seat, but you also have to push a ton of people out of the way, and hope the driver gives you enoug htime.4. Many buses have the wheel well right under 2 rows of seats, so unless you are a kid or a shortie, the window seat is to small to sit in.5.  Also, some busses they never measured the seats properly, and any tall guys like me may not fit in the seats and have to stretch my legs in the aisle.  Sometimes I wish I was one of those tiny girls that can fit in anything. -- dandmcd