I can feel a binary view on this - it rasies some very strong emotions in some.....
The seat reclines and you are in it. You are entitled to recline it and do so without intimidation from someone behind you.
As someone said in the thread just do it slowly..... I had an exploding laptop screen one time when someone slammed it back, the screen got caught on the tray table clip and flexed.... sigh.
Unfortunatley there are always those who donīt see it this way