You obviously don't know any good teachers. My wife is up till 10:30 to 11 every night grading papers and making lesson plans. Of her 3 months off in the summer; she teaches 6 weeks of summer school, 3 weeks of seminars, conferences, and continuing education (required).
Not all teachers are as dedicated, but then again, not all teachers are union loving deadbeats either.
Kudos to your wife. Sounds familiar. :)