Meiklour, if you associate commuting with fatigue then you must look at the whole working block. That's not muddying the waters as you say. You cannot single out commuting as 'fatiguing' by just looking at one negative aspect and disregarding all the other factors. Muddying the waters is arguing that FTL's come into play for something we do in our spare time!
Where do we stop otherwise?
Can I go for a run in the morning before a flight? Can I drive my children to school? Can I visit my parents who live two hours away from the airport before reporting for an afternoon flight? Can I manage my own company before leaving to the airport to work?
And yes, you had a horrible commute to Frankfurt, but that is absolutely not the norm. Leave it up to the individual to decide wether their commute is fatiguing. Personally I find running a family and working 'from home' far, far more fatiguing than commuting. Commuting was the saving grace when we had a newborn in the house.