Don't get me wrong, I usually sleep or read entertainment stuff (recently for me: either Pratchett or Iain M Banks - I heartily recommend his excellent Culture cycle, BTW) on airplanes, but what this is about is giving people choice in the matter. If you want to relax and "enjoy the peace and quiet", fine ! if you want to connect to the global planetary network, be it for work reasons or entertainment too, you should be given the choice.
I get what you're saying - but you can't say to people they *have* to relax just because they're traveling. I've co-founded and currently lead a small computer sciences startup and given the choice, I'd much prefer to read or sleep when I'm in an airplane. However, there were several times when I *had* to work (in my current job as well as the previous, more traditional / employed one) during travel to make sure I was ready upon arriving, just because I didn't have time before that to do it
Basically, what I'm saying here is: the more choice people have, the better. They might use the network to read their favorite news site (slashdot or some twitter feeds or other), or they might use the network to work, or they might simply relax using an old-fashioned book. The point is, if you add Internet connectivity to your flight, you are simply giving them more choice in the matter, which is good in my book.