The controlled chaos of Oshkosh is substantially different (and much safer) than a bunch of morons blasting around uncontrolled airports.

If we are ready to start with people around an airplane on either side of us, we always try to start the opposite engine first. If we're pulling into a parking spot and there's somebody on either side of us, we try to shut that engine down before rolling into the block to decrease noise & improve safety.

As you say, a little professional courtesy goes a LONG way