Look at this. They get full benefits and are paid around $40k/y to work about a thousand hours a year. That means that, in terms of effort that goes in versus money that goes out, they are paid about like a decent programmer on average. If my experience was at all typical, most of them do a terrible job and don't even try to do a good one. Throw into that that there is a mechanism specifically designed to ensure they don't have to do a good job (tenure), and it's a pretty sweet deal.
I would say being paid comparably to one of the most highly paid professions in our country while not being held to any real standard of quality and, in fact, being explicitly shielded from any such standards puts teachers in the category of "overpaid" rather than "underpaid." If a government wants to cut costs by bringing their pay into alignment with the value they deliver (or at least improving the alignment), then so be it. Don't like it? Find a different job.
Most of the people who should be teaching children probably aren't in it for the money anyway.