I know a few teachers. They work hard at the start of their career but once settled with good course work and better time management they don't do more than 40hr weeks and are fairly flexibly with their time. E.g., they might work until 7pm on some week days to get marking done and then leave at 4pm the rest of the week, or work all Saturday but leave 4pm all week. Longer hours near exam time and at the start of term but most don't find it too much work at all.
You also have to consider that 50+ hr weeks is common in many industries where the holiday entitlement is a fraction of what teachers get.
You also have to consider that 50+ hr weeks is common in many industries where the holiday entitlement is a fraction of what teachers get.