Ethics are always worthy of discussion, so long as people don't get all emotional because somebody disagrees. Face it: Some folks can type faster than they can think. Bummer. Some folks go to nit-picking to the point that it's a lot like picking fly-poop out of pepper, and that ain't gonna make for a remunerative career.
My understanding about carp, buffalo and gasper-gou is that they eat out the bottom growies which are both food and cover for fish which are themselves food for bass and such. I won't swear to that, however. Read it somewhere, Lord knows how many decades back. Carp seem to be the worst.
When Texas P&W did the rotenone thing on Lake LBJ back around 1970, I saw carp as much as five feet long and almost a foot in diameter. People with reefer trucks were buying them. I disremember; 8¢ a pound? Something like that. For cat food.
"A weed is a flower in the wrong place." Sorta like feral cats vs. house cats. House cats shouldn't be out in the pasture killing quail. House cats in or around the house don't get bothered, I've noticed. Dogs oughta stay home in the BossMama's yard and not out chasing deer or killing sheep.