The concept of common sense is a long-standing term, based on human experience and people's individual perceptions. Common sense isn't actually common, in either sense: it is different from person to person, and may not be employed even when many editors could agree on what it is in a particular situation.
Thus, when discussing issues of importance to projects on Wikipedia, don't consider your position, or the position that you agree with, or even a position that has consensus, to be "common sense", because it's nothing more than your perception. Your idea of common sense is likely to contradict someone else's idea of common sense.
Instead of relying on "common sense" to make decisions, you should instead rely on building consensus for your position and perception, and work with other people to reach a conclusion most people can accept. By assuming your position is "common sense" and acting upon it, all you're doing is insulting the people who disagree with you.
