So, you object to an entire profession because a few might be abusing sick leave?
I'll affirm it. Yes, they do. It's true, You are correct.
I personally know a few folks who do it. Golf every first Tuesday. "Mental health" days at Lanikai, and "sick" around Christmas and New Year to get the cheap Vegas air fares. 
So, ALL teachers must abusing sick leave, too. Is that the logic?
Seems so in your perspective.