Well, to be fair, where does it say that anybody can vote?

https://en.wikipedia.org/wiki/Article_Two_of_the_United_Stat...

So, if your state legislature chose to appoint electors by lottery, that would be acceptable under the US Constitution. Other options: appoint the oldest people, appoint the richest people, appoint the people who live closest to the center of the state, appoint the heaviest people, appoint the people with the longest tongues...