Perhaps some day there will be an airline that installs non-reclining seats throughout their fleet and proudly boasts, "Our seats don't recline!" Somehow, I don't think they would be very successful.
That airline would be Ryanair. Their profits were up 30% last quarter:
http://www.ryanair.com/site/about/invest/docs/present/quarter1_2006.pdf
The primary reason that Ryanair has ordered their new planes without recline is that the seats are less expensive in the first place without it, and they also don't need as many repairs. (They have also eliminated seatback pockets and window shades for the same reasons.) However, on the subject of the reclining seats, Ryanair are actually are getting some mileage out of the fact that no one will lean back and squash you. (They are locking down the recline function on existing seats as part of scheduled maintenance.)
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I personally believe that the recline etiquette problem exists because the maximum recline degree that coach seats have is about the same as it was 20 years ago, while the pitch has been greatly reduced (and yes, I'm aware that the seatbacks are much thinner now.) That angle was fine when the pitch was greater than 34", but when you are scraping closer to 30", it becomes a tyranny of parallels, which is why you also get so many people ticked off about passengers behind them levering themselves up by grasping the seat in front. If the seat is not reclined, it's possible to lever up using the armrests, but if it is reclined, getting to your feet without grabbing that seatback for balance becomes something of a contortionists' trick.
RE: the tray table use not being affected by the angle of seat recline: Not really true, especially if the seat has been forced back so hard that it has slipped the gear stop (a not uncommon thing). Again, design has not caught up with the times. In the old days when the only thing that landed on that tray table was a plate of food that was carefully set up not to be more than 2" high (remember the really shallow coffee cups?), the only problem was the possibility of dropping food on oneself in a moving aircraft because of not being able to lean a bit over one's plate. Now that airlines are leaving us all to bring our own food, the height of it is a bit less predictable, and it often ends up nudging the reclined seatback. People now expect to be able to put taller things (up to about 12" tall, like laptops) on that tray table, and a fully reclined coach seat just doesn't give that much clearance.
FWIW, when a child kicks my seat, I tell him directly to stop, and it almost always works; there is a shock factor in being spoken to by a stranger. I also NEVER let my own child do it to other people. The one and only time DS tried to defy me after being called down on the seat-kicking thing, I fixed his little wagon with the somewhat oversized pr. of sweat pants he was wearing; I stretched them down past the ends of his feet and folded the ankle ends back under his tush. Since he was strapped in a carseat, those feet were not budging, and it didn't take long before he realized that Mom meant business. Yes, it was uncomfortable for him, but it taught him that seat kicking was something that I could and WOULD prevent him from doing.