To my knowledge, I'm not a slow reader, nor do I have an unusual amount of patience (quite the contrary), but I can't imagine making it through a magazine, much less a stack of them, during the time I usually spend unable to use electronics on a plane.
I've heard the occasional story about long tarmac waits in New York, but didn't realize that 45-60 minutes could be anywhere near typical. Is Newark any better, or basically in the same boat?
Of all of these hubs, I hold a special pocket of hatred in my heart for my hometown airport, LAX. It's not the biggest or most crowded airport in the country, but it seems to be the worst run. Security lines take at least 45 minutes a pop, even if there are only about 10 people in line. Pre-takeoff delays on the tarmac routinely run 60 minutes or longer. Etc. It's about as well-managed as a DMV, and every bit as infuriating.
SFO tends to suck, too. I'm actually surprised you haven't had worse experiences there. It's routinely rated as one of the worst airports in the country for delays. (SJC, by comparison, ranges from painless to downright pleasant).
if someone's a frequent flyer, the routine is going to get monotonous. You'll need a moderate stack of magazines if you're stuck on the runway for another half hour. Change planes once or twice, and you'll really be wishing you had a lot more reading material. magazines are generally half ads, so you'll get tired of those reading those.
Overall, I sort of agree with you - it seems a little over the top, but it's probably not unreasonable for many people. A stack of newspapers would be lighter, but they're usually too big to deal with for extended reading in economy/coach seats.
But from what I understand a big reason for the "taxi, takeoff and landing" routine is that somebody completely absorbed by their iPad is the last thing the crew want when things to pear-shaped, and when this happens, it's at these points rather than on cruising altitude. Now of course you might the same argument for a book (although it's a strong one for music players), but just my $0.02