All ballots should come with a "No vote" option. What would the difference be from just leaving it blank? Nothing, except that it would give uninformed people a box to tick so that they don't have to stray towards the more important ones.
With that said, his stated corollary (to vote against propositions by default) is unhelpful and perhaps harmful. Many ballot proposals are stupid. Some aren't. As a voter, if you don't have an informed opinion, the right move is to leave it blank. Don't vote. Leave the job to those who have done their homework.