"Wasted" is different than "losing." In FPTP, my vote only goes to my local candidate; if he or she loses, that's the end of my vote -- it's "wasted."  In PR, my vote will always count towards my preferred party, even if my party finishes last (as long as it's above he threshold). Also under FPTP, if my preferred candidate has no chance of winning in my riding, I might as well not vote; my vote will count for nothing. But in PR (including MMPR), it will go towards electing my preferred party.