Being of average height, this is not such an issue for me but let me throw a little JetA1 on the smouldering cigarette butt left in the toilet ...
The reason that I rarely recline the seat is that it makes so little difference. Even on long haul, the very short distance that it reclines makes almost no physical difference to the body - it seems to me. The effect of the recline, I often think, is more in the mind.
Unfortunately, the people in front of me usually consider those few degrees of recline to be vital to their way of life.
Airlines greedier? Only because people will not pay for more space. AA rather famously had a biiiiig campaign to remove Y rows and open up the pitch. TV adverts showed them physically throwing seats off the machine. So - rewarded with extra bookings? Millions flocking to get onto these new open fields? As I understand it, they have now (quietly) reversed this policy.
Predominantly, people do not want to pay more money but will bitch about the lack of space. Given the recession that the UK and USA is now in, do not expect this to improve any time soon. If you travel SH from the UK, use RyanAir as their seats do not recline.