That's probably because most people have ridiculous commutes. Even if you only commute 30 minutes each way, and work 8 hours a day, it certainly feels like you've worked 9 hours that day.
(Compute "Working and work related activities" - "Working", but that's actually an overestimate, since there are more work related activities than travel.)
The overall average is a poor metric to use in this context.
How many jobs do you think are out there are are expressly limited to 40 hours a week to avoid over time? Or 20 hours a week to limit having to offer health insurance?
I'd be far more interested in an average for "professional" employment paid on salary, it would be far more telling.
Working 11-12 hours is definitely not common. Of the few people I know who do it, all do it voluntarily.