If someone only gives 10s or 1s to everything, their vote of 10, should probably have less weight, than someone who distributes their votes more evenly.
This is not correct. Many people dont bother to vote or review unless the movie for them is at an extreme goodness or badness, so the hassle is worth it. I ve watched a lot of so-so or simply good movies, but I only have voted 5-6 times and those got either a 10 or a 1.