2 points:
First The salary is equivalent to £29k. If I work two days a week and earn £20k - yes I only earn £20k in my pocket so less than my colleague who is earning £50k!!! BUT she is working 5 days a week, not 2. Not a difficult concept.
Just as I can do something else with my "free" days, (other work, childcare, hobby, money-spinning crafts...), so can teachers. (I have teacher friends who work over the summer running summer holiday clubs, tutoring, doing paid walking holidays in Italy ... etc)
Teachers work their hours, they work hard and do a good job. They are paid for their hours - not for doing nothing over the summer. Don't be so resentful. I am sure you al get paid for the hours you work, whatever thy may be, and you all take holidays.
Secondly - other professions DO get criticism. In fact it is horrible the way people speak about social workers, doctors receptionists, health visitors, any HCP, estate agents, letting agents, bankers - to name but a few.