What's the point?
The point is that it's fun.
Killing the common carp is good for the environment.... AND it's good for the remaining carp. Think of it as Quality Carp Management.
Releasing a carp is nice to that individual carp, but it doesn't do anything to improve carp fishing (either angling, or bowfishing). In good habitat carp quickly overpopulate and become stunted. (even a popular European carp fishing magazine called American carp overpopulated and stunted)
I do enjoy angling for carp when I'm not trying to impale them with fiberglass arrows.
Even when catching carp on hook and line, I still clock them on the head and use them for fertilizer. There are just too darn many of the things. Even a couple less carp is a step in the right direction as far as the river ecology is concerned.
I eat some carp, give some away to other fishermen, bury some, make 'coon bait with some and I do throw some of them away. Carp are tasty when caught out of cold water, brined and then smoked. (really!)
Bowfishing; cleaning up our waterways, one carp at a time. 