Basically, if you vote on a single issue to change speed limits everyone having the law inflicted upon them is also a voter. Or at least a hairs length away from being one if you get your license as fast as possible at 16.
If you vote to defund public schools so the power goes out intermittently and there is black mold in the ceiling and cockroaches in the lockers, you are directly harming those who have no say in what happens to them.
It comes back to general issues of regional politics in a global world. If China wants to manipulate their currency and violate IP or if Russia wants to invade and conquer its neighbors or if the US wants to occupy countries for decades on end the citizens of, say, Greece never had anything close to a say in any of those happenings but are still subject to the consequences of them. Just because you get to write your own laws doesn't mean those without a voice in your decisions will be heavily, often negatively, impacted by them.
In the US that problem is more pronounced, because the freedom of movement within the US means that states that actually educate their population have to deal with the influx of uneducated that enter them when their economies prosper with an educated employed population and the states that didn't educate their people have crippled economies incapable of growing because nobody can read beyond a 4th grade level.
They should to a degree, but of course it depends on the level. Plus, having an educated population is good for national and economic security. Really now more so than ever in our history given the competitive landscape of the world economy today.
In other words, as a national security issue, I don't believe states shouldn't be allowed to neglect education as much as some have. One of the pillars to building and maintaining an economic powerhouse is a well educated population.
Education is a classic state issue. Why shouldn’t people be able to deprioritize it?