While I agree it is important to play well with others, I don't think it is realistic or even possible to not piss people off on occasion.

Some folks are never satisfied no matter what you do...
Some folks don't deserve the effort it takes to get along with them...
And if you don't piss off some folks every now and then I'd be inclined to think they must be pissing you off royally and it is just being bottled up inside waiting for a high caliber release........

You can make some of the people happy all of the time,
You can make all of the people happy some of the time,
But sometimes you just piss people off.