Because most voters aren't making the minimum wage. So say the minimum wage is $10, but you're making $16, and the min wage gets brought up by $5 to $15. The person making $16 an hour isn't going to get a raise, or if they do, it won't be a $5 raise. They'll just be making $1 over minimum wage, only now everything in the state will adjust upwards in costs, because capitalism. Rent rates and used car prices will go up. Groceries will get a bit more. Places will charge more for child care.

If you weren't making close to minimum wage, it hurts you more than it helps.

This is a perpetual problem. The fix is simple. Instead of trying to make low incomes higher for a short term amount of help; tax the fuck out of the top end. That will lessen the burden on everyone else, provide more money to help those in need, prevent the oligarchs from just trying to hoard their wealth and put it back out into their companies rather than paying more in taxes, etc.

In short, raising minimum wage is a dumb thing to focus on, when the real focus should be on lowering the top.