The Hogwan Owners association in Korea puts immense pressure on all Hogwan owners to conform to a rigid set of terms and conditions that encompass the employment conditions of all english teachers. I know from my own experience that 30 teaching periods per week is insane and unsustainable outside of a couple of weeks. Most Hogwans in Korea are corrupt and will systematically abuse their employees terms and conditions of employment at every opportunity.
If you truely believe what you wrote then I think you are either a Hogwan owner/brown noser or a deluded or naive westerner.