To me just putting my seat back ONE notch is a OK, I'll normally look over my shoulder to make sure the dude behind isn't leaning forwards.
The putting of a seat all the way back however is rude, yes, the seat is capable, yes you've paid for it but it is the equivelent of doing 50mph on the motorway or 40mph in a 50 zone. Or pushing into the front of a queue. Just plain annoying and not the norm. If the person in front wants to do it, then that's their decision to be an a$$hole and depending on what mood I am they'll get the response that I decide at the time I think is appropriate.