Low voter turnout is not a universal problem. There are a lot of places where voter turnout is very high. America just does a really bad job of it for multiple different reasons.
We can't hand-wave it away as "oh those people would never vote, no matter what". There are reasons they don't. They're not always good reasons, but some of them are.
We can talk about multiple problems at the same time. We can talk about bigger problems and smaller problems at the same time, acknowledging that one is more important to solve than the other. We don't have to say "I won't talk about this problem until we've solved that problem".
And for the record, of the people who don't vote, it is a tiny fraction of them that genuinely do it because they don't think they're smart enough. And those people are usually wrong, because while they may not be geniuses, there are people a lot dumber who ARE voting and why the fuck would you leave it up to people dumber than you?
Remember: decisions are made by people who show up. And people a lot dumber than you and me and the non-voters are showing up