I vote in pretty much every election for which I am eligible, even if I don't particularly like the way the system works. I'm fortunate to be in a position where I can fairly easily make it out to the polling place regardless of when the election happens to fall. But not everyone can.
current Michigan rules say that you must apply by the Saturday before the election. That doesn't sound difficult, but if the reason you're voting absentee is that you're very busy with work and travel, it's tougher than it sounds.
In Michigan, you can only request an absentee ballot if you meet certain conditions (copied from those same current rules):
Nowhere in there do I see some pretty common reasons that someone might want to vote absentee. "Out of town unexpectedly," for instance. Or maybe "Kid got sick and had to stay home." How about "Work schedule leaves only a short window when polls are open, and other commitments cover the rest." And there's always "Lines at the polling place are incredibly long and I can't afford to wait for hours." Life doesn't stop just because the government schedules a single day to vote.
Several states already conduct all elections by mail, which is effectively absentee voting for everyone. This makes the most sense to me. Not only does this allow people to vote on their own schedule, it also saves a lot of hassle in setting up polling places, getting volunteers to run them, and so on. It also makes it more likely that voters will make more informed decisions, since it's easier to look up some candidate you've never heard of when you're voting at home with plenty of time.
I'd like to see a lot of changes to the electoral system, and I realize this is a fairly minor one in the grand scheme of things. But it's also a fairly easy change to make, since absentee mail-voting already exists everywhere. It's cost-effective, since it eliminates a lot of polling-place costs that should more than cover the expanded mail-voting system. But it doesn't seem to be a priority. I'd be a lot more likely to listen to a politician if they're speaking out about changes like this that improve our system.