My Scantron Election Ballot

Almost every american has attended some form of education that required them to take a test where they filled in little bubbles for the correct answer. Why is it that the ultimate multiple-choice test of democracy, voting day, we the people thousands of weird and obfuscated ballots and voting machines?

Why not just fill out a scantron ballot?

Its a physical ballot that can be (very) quickly counted electronically or tabulated in person. Each ballot can be uniquely encoded so that a person can double check their results online but maintain the secret ballot. Anyone who's taken a test is familiar with the format of A/B/C/D/E. Its just so obvious! And cheap! And hard to defraud!