I'm really hoping you are joking, or your ignorance is just over-whelming. Infact, it's mildly offensive.
My other half is a teacher, and she gets into school at 8am and doesn't leave till around 6pm - where you get 9 to 3 is beyond me. She gets home an hour later and does planning and resource planning for at least 3hrs outside of her work hours.
She works more hours than me as a designer on an average week unless I have a huge project or deadline to meet. She doesn't get overtime, and she works over the weekend to boot. She plans and sets up her class-room two-weeks in advance of the term starting, meaning she really only gets around 3 or 4 week's break over the summer. This will be the same for any decent teacher who cares about their profession.
Your 'glorified' baby sitting is in reality taking care of 6-yr old children that have problems of their own. Some are gifted and talented and do as the teacher asks. Some have no/divorced parents, abusive or neglected parents, a parent who is in jail or who don't earn enough to feed their children. Taking care of them, their emotional, physical and educational well-being for the future and the over-bearing, rude and ignorant parents is more than just a simple drain on her mental health. During lunch - she doesn't sit around, she either is planning again, or taking lunch duty outside in the bitter cold or going on a training course.
To top it all off, she is not over-paid at all and barely makes rent/food each month.
Whereas myself as a designer, almost earns double her salary to sit-down for the majority of the day, in a warm nice building infront of some amazing technology, listening to music and not have screaming kids pulling and demanding of me all day. Wait - I deal with clients, so maybe that last part is wrong
So, still think teachers are over-paid with an easy job?