"You don't want someone changing their vote because of how the polls are going. You know, you want them to vote based on their own beliefs, not who is going to win."

That idea makes sense in true proportional representation system, but in a first-past-the-post system then strategic-voting becomes important (as voting-for-beliefs is an immediately suboptimal strategy), and therefore if voters know who is currently in the lead and alter their voting behaviour then surely that's a good thing for democracy?