> Because at first read, I'm not sure how ranting about "ignorant people to cast poorly-informed votes" is different than "I don't want those people voting."

It's not, and therefore the only 'fair' way of conducting elections is to make sure everyone has the opportunity to vote - even the people who will vote for the candidate you don't like.

A high turnout also has the advantage of inserting noise in to the result, negating the unfair advantages of highly motivated time-rich people (usually older people).