For me it's a lot of reasons.
1) the peace and quiet of a still morning / afternoon on the water, listening in and seeing nature doing her thing.
2) the memory's of childhood days spent catching HUGE trophy class bluegill
3) the challenge of outsmarting a bunch of pretty dumb fish.... who can regularly make me look like i don't know my ***** from a hole in the wall.
4) the thrill of running down a lake at wide open throttle, wind whipping in my hair, hunkered a bit behind the center console, praying a floating log don't ruin my day much less my life.
5) The pull of a good fish on the end of the line... not knowing if you and all your techno stuff or the fish will prevail.
6) The satisfaction when it's you.
7) The Dammit All when its the fish that wins...
8) Filets... and HOT GREASE!
9) To crush your enemies, see them driven before you, and to hear the lamentation of their women. (wait... that's from something else...
)
10) probably most importantly to hang out with you kids / buds / family / friends.