That's the pesky thing about democracy, you see. If you want "informed voters" then you actually have to work to have an informed populace, not gripe about people's right to participate in the society they're a part of.
Not everybody has to be your idea of an intellectual to be a part of a democracy. And not only is that okay, it's precisely the point of it being a "democracy".
Yes, and the solution to this is not mandating that they vote. If they are uninformed forcing them to vote doesn't cause them to be informed. It makes the system more vulnerable to populism.
The idea behind freedom is not absolute freedom. It is a balance of the contract with society vs individual freedom. You want to maximize individual freedom, but for everyone (not a singular person). Clearly things like the "freedom" to murder someone doesn't outweigh that person's individual freedom to live and thus we make laws (and ways to enforce them). Mandating voting decreases individual freedom and has a potential for reduced societal freedom (while little to no real potential for increase. Much prone to populist candidates). So why mandate? Don't solve problems that aren't problems. If someone doesn't want to vote, how does that harm you?