The problem with the electoral college is not that they vote in place of the people, it’s that states are winner-take-all. This means that in states that have a solid majority of one party (red state or blue state) it is essentially useless to vote if you don’t happen to be in your state’s majority party. Gerrymandering works to solidify this system, but that’s a whole topic of its own. Only in the 14 states that go back and forth (purple/swing/battleground states) do the votes really matter, since they can make the difference between the state going red or blue. Candidates will pretty much exclusively advertise in these states because it is the most efficient way to spend their campaign finances.
In the case of voting, there have always been efforts to skew the correlation between being a US citizen and being a voter. It sounds politically charged, but the genuine truth is that the vote was skewed towards being more available to citizens that are better off. Usually, white landowners who are at least mildly wealthy. There are many possible motivations for this, and it has likely varied from one influential person to another, even amongst the founding fathers. It’s even fair to say that not all founding fathers wanted to have wealth-based prerequisites to vote.