I'm not driving into the law school just for that meeting.
Sorry, that's my day off.
I didn't ask to be on that committee and prefer not to serve.
Whatever course of action others decide to take is fine with me; you don't need me there.
Attending a meeting at that time disrupts my writing block.
I don't work well with others.
If I start engaging in service work, the dean might ask me to do more.
I'm paid to teach and to write; let others do committee work.
Most of us have one or more colleagues who shirk committee service, which can lead to this inequitable result: those who do serve are asked to do more, and those who resist serving get their wish.
What's the remedy? A pay cut? A private tongue-lashing? An increased teaching load? Or might circumstances justify the avoidance of committee work (e.g., the colleague who consistently out-publishes the overwhelming majority of his or her colleagues)?
I'm curious to know how your administration addresses this issue.