Sure, there's about 2-3 months "off" between when class ends in the spring and class starts in the fall.
However:
They don't get flexible vacation time off the way others do.
Not all of that "time off" in the summer is truly time off, as there is work time staff are required to be at (particularly the couple weeks after class ends and the couple before it starts again) , professional development, etc.
They also generally are working more than full-time hours during the school year. When you average out their hours over a school year, it ends up coming out comparably (or greater) with other full time jobs.
One of the common misconceptions most people have is that if school is not in session, teachers aren’t working. That couldn't further from the truth.
www.boredteachers.com
Also, with a relatively small window of time there, the job itself makes it harder for someone to earn other income during those couple months. Holding that against them seems problematic.