Cetaceans are highly intelligent, supposedly more so than other mammals that we eat, which I think counts for something. If not, why stop at whales? Why not primates? Why not other humans? Have I made my point?
-As far as I can tell, most research indicates that dolphins and orcas are, as such things go, pretty bright, perhaps even sentient.
Sentience would make me wary about hunting them, but as far as I can tell, no such claim has been made about minkes, which are the whales hunted locally.
The problem, by the way, with such an argument as you're presenting is basically that it leaves us to choose an arbitrary cutoff point. Which species are intelligent enough to warrant not being hunted for food? Why at that precise point? How about an unusually bright specimen of the first species deemed dumb enough to hunt?
Basically, the only safe conclusion would be to go vegan. (Which I can see valid arguments for, though they haven't as of yet convinced me.)
We do, after all, kill other mammals for food which -if one can use such a word- intellectually are at least on par with the whale species hunted without much by way of outrage from the public.
So - what is so special about the whales?
(Full disclosure - Norwegian, we also hunt whales; while whale meat is by no means an everyday occurrence, I tend to eat it 4-5 times a year, which probably is above the national average)