Well, who exactly are "the people"? The various states each have their own rules how the will of "the people" gets measured.
Some have caucuses, where the party faithful get together and somehow debate until they come up with a winner. These states are somehow difficult to predict.
Other states have primaries, which can be open to all voters, or closed to only party members. Closed primaries don't have to be really closed. In some states with "closed" primaries all you have to do is say you're a Republican. But you can make that declaration at the time of the primary and it doesn't hold any weight.
Some states are "Winner takes All" states. In Florida, Trump could get 36% of the vote vs Rubio's 35%, and Trump could walk away with 100% of the delegates. Or reverse the numbers and Rubio would get all the delegates. Is it fair to the 35% of Florida Republican Primary voters to have their votes count for nothing?
You can argue that the candidates know the rules going into Florida and every other state, so it's fair to them to have some of their supporters' votes count for nothing. But that leads us to the contested convention. That's just as much part of the rules as leaving the "loser's" Florida primary votes on the floor.
If Rubio wins Florida and Cruz wins some other states and Kasich wins one or two and they all keep Trump from getting enough pledged delegates to win the nomination on the first vote at the convention, then Trump LOSES the first vote (they all lose, of course). There is no winner. Rules were followed, and on the second and subsequent votes none of the delegates are required to support the person they were pledged to. Perfectly fair, and all according to the rules, which all the candidates knew going in.
Trump can become the nominee without ever getting 50% in any vote, but he's not guaranteed, or even deserving of being called "the winner" by those rules.
