Perhaps being of a certain height gives one a different perspective...
I'm 6'5". I do not recline in coach, even though it might be more comfortable for me, because I am aware of what it might do to the person behind.
Like OP, in E- my knees are already against the seat in front of me. I can potentially get them out of the way by contorting the rest of my body. But a sudden recline causes great pain. And the ability to heal quickly seems to decline with each passing year.
Back on point: In First, I generally only recline if I am going to try to sleep, unless I am in the last row. It may not ram the seat into the person behind, but it does make it harder for them to get in and out of their row.