....... Always wondered if the big ones get shot....
That very well could be.
No way all of the 40+ are getting shot. I've shot quite a few pike back in the day and the biggest I've shot or seen shot were around the 35-36" mark. The most active breeders I believe are in the 32-36 range from what I've seen in the flooded woods in the spring. Actually have seen lots of much smaller pike, too, which I assume are the "bucks". The 40's are just rare specimens.