Reason(s) "I" don't or won't vote:

[KAPital PHINUst]

This one came from my former roommate when I was in college:

"Voting is just picking the lesser of two evils"

I tell him: You don't like a particular candidate, write somebody in that you find to be the most qualified. While they may not count the vote in the tally, you get to exercise your civil duty and (possibly) make a statement regarding your selection.