Along with several others, I can't see much wrong with using whales as food. That's my philosophical position, and I am setting myself up for a heap of shit.
I do, however, have a problem with catching them right NOW, because they have been commercially 'fished' almost to extinction, and if they are not left strictly alone to recover, they may never do so. Who can tell if the whale that's harpooned tomorrow might be the most genetically important one left? Arbitrarily reducing the size of a already reduced gene pool is bloody stupid. They only procreate like other big mammals, not spawn like fish.
Just because you can see 'plenty' of them, it doesn't mean there are lots of them. It is possible that you see the same ones over and over, as is the case with territorial whales.

Non-whaling (ex-whaling) countries do tend to be a bit unbalanced about whaling, though. AFTER it became uneconomic, they swung the other way as conscience prodded them to to try to 'Save the Whale.' Now they try to lean on subsistance whalers to comply with their position.