My standard answer when requested not to recline my seat is:

"Sure. I paid $----- for my seat. If you want to reimburse me for that amount, you can tell me how to use my space." No one has ever taken me up on the offer.

Just as your seatmates don't ask for your dinner because they are still hungry, or put their carryon bag under your seat because they need the room for their feet, they shouldn't ask you not to recline.

You wouldn't let your neighbor tell you that you can't park in your garage because he needs the extra spot for his car, would you?