The methodology of actually hunting and killing whales is absolutely horrendous. Now, to be fair, chickens are often treated badly too but that’s at least somewhat manageable/reducable, there’s no way known to kill a whale that isn’t basically horrific.
The main difference imo is literally the nature of the beast. Chickens are small brained, less complex animals. Ceteceans are smart. (lumping them all together btw, some of these things we don’t see all types of cetecea do) Anthropomorphising is always dangerous but we’ve observed them at play, living as family units, communicating, learning, working as teams in really very clever ways, and showing behaviour that looks very like mourning. They’re inquisitive, they use tools, and they get bored, and irrirated. And we know they remember, and plan for the future. They seem to show self-awareness- studies suggest they recognise themselves in mirrors and videos. Do they experience life differently to chickens? I don’t think many people would doubt it, and that makes taking that life a different matter.
(there’s a definite possibility that some ceteceans are smarter than us; denser cortexes, and faster brain stems. Literally more processing power and bandwidth. Not to mention having access to sensory methods we lack; what new things would humans think of if we could perceive sound and space as echolocators do?)
TBF, I’d rather farm humans.
Is there a sliding scale of harm and of acceptability? imo, there is- everyone draws the line somewhere. Vegetables grown with herbicide are murder! Personally I only eat meat that I know has been cooked alive, the pain makes it tastier.
But we should be treating farmed animals better. I’m personally comfortable with murdering meat. I’m comfortable with it being basically unpleasant for the poor buggers. But I don’t want it to be cruel, or needlessly unpleasant.
Specifically on the subject of japanese whaling, what’s weird is that they don’t even make money off it; the whaling fleet is dependent on subsidy. And the quantity of meat exceeds demand.