Not everything can be left to "the people's will". If we let everything be decided by a majority vote, we'd have tyranny of the majority on every single issue. Judicial review is designed to protect the Constitution, which in turn protects the rights of all Americans, not just the ones in the majority. We're not a direct democracy. The system is specifically designed to prevent mob rule just as much as it's supposed to prevent dictatorship.
Put it this way: how would a plebiscite on civil rights have fared in the 1950's? How would a plebiscite about school prayer fare today?
The "will of the people" is not allowed to trump the Constitution, and the judicial system is supposed to keep the people in line with the Constitution, not the other way around. There is an amendment process, after all. If "the people" can't muster enough support to get an amendment through, then clearly it's not that vital an issue...and certainly not one worth disposing of the entire philosophical basis of American law!