Like Kois, and like Merlin, I’ll almost never recline my seat, except on long overnight flights where everyone is expected to be asleep.
It’s a tiny, insigificant form of protest, but it’s a small contribution toward reducing the world’s total annoyance. I think of it like social environmentalism.
[In this case I’d take it one further. I don’t fly unless I have no other choice. The entire experience is awful with one general exception… speed. There’s no faster way to get some places. Even before the TSA existed I stopped flying to Montreal. For a while I ran a dev team there. Every few weeks it was time to check in more personally. I started out flying. Took 5 or so hours with all the usual stresses and costs for a flight time of about an hour. When winter weather was poor it took much longer. Driving always took about 5 and half hours, wasn’t as affected by the weather and gave me the peace of listening to a decent car stereo, controlling my schedule, and reducing cost. Everyone thought I was a heretic. So don’t just not recline, avoid flying if at all possible. What should be banned is the airline/airport experience as it is today.]