The current method of open voting on RfA is terrible, btw, and causes a great deal of hurt feelings, log rolling, and clique development.
Jack (Sam Spade)
I am the only one who feels that votes for adminship is a slightly different matters than other polls? You are discussing a particular individual, and it gets a lot more personal than discussing other matters. Saying that voting yes is to agree with the nomination and voting no is the only version that needs to be explained is really to ask for rough behaviour against those who oppose the nomination, like Jay describes. If I know that if I vote no I have to give a motivation, someone will think I am cruel and the consequence is I get into a hailstorm - then maybe I choose not to vote.
Maybe you need either a culture where the votes are always motivated, really _always_ and votes that are not motivated are removed - including votes agreeing with the nomination - or an exception regarding votes for adminship. The election for the Wikimedia board, that recently was finished, was done not only without motivation but closed, so you did not display who you voted for. In Wikipedia context, with the ideals of concensus etc. it would be interesting to hear why this method was chosen.
/ Hab