Contrary to what many persons assume, during the voting process many persons do not vote for the party whom they would like to see as the winner. Many persons vote based on whom they want to see as a loser.
Given the often poor choices of candidates and parties, a large number of voters will vote against certain candidates to ensure those candidates do not win. This is similar to the many citizens who simply choose not to vote given the poor choices.
The proposed changes will effectively remove this option which voters currently possess as their voting right.