*unemployed* my foot.
One would hope a teacher would be able to figure out that if you're only getting paid during 10 months, you put aside some each month to get through the summer. Plus, they can get a summer job in addition to their teachers salary.
You're right, it's not "unemployed", but it isn't "paid" time off either like my wife or others get for their jobs. Many teachers do use the time to take classes and such which they do pay for.
But I will say, that's what you expect as a teacher and teachers full-well know about it when they become one.