First off, I find it ridiculous that so many say they don't care about acceleration... I find this measurement a useful tool when selecting a TV... A test drive will most always be non towing, and a truck that feels peppy empty can turn into a slug when towing.
And yes some may be satisfied towing at 50-60 MPH... But not everyone lives life in the slow lane.
And even for those that do...Think about happily towing at say 50 MPH on a winding two lane highway, and coming upon a large truck struggling to make 15-20 MPH. And just enough oncoming traffic to make passing a challenge. It happens more often than you may want to admit. Some extra acceleration sure could come in handy under this scenario.... Oh but what the heck, it may only be 60-70 miles at 15-20 MPH vs 50 MPH. What's a extra two or so hours.
Have you ever noticed that those poking along SLOWER than you are morons, and those passing you are idiots?:B
And there are very few good drivers going the same speed as you?