I dislike Sea Shepherd as an organization, due to their distasteful methods (and personal bias, being a Faroese resident). But I spoke with several of their volunteers during one of their campaigns, and was pleased to realize that, as individuals, their hearts are mostly in the right place. Nearly all of them claimed to be vegan, which I feel does give you legitimate ethical grounds from which to criticize grindadráp.
However, if you don't oppose the general consumption of meat, I don't find the argument against grindadráp compelling. It yields more meat per killed animal than most, and the slaughter itself is arguably no less humane than most commercial meat production (not a high bar, I admit).
In terms of publicity, grindadráp suffers from being inherently more visible than commercial meat production. Personally, I think this is a positive thing. It confronts you with the fact that meat doesn't magically appear in a supermarket freezer - if you want to eat meat, then by definition a living animal has to die. The visibility of grindadráp has prompted conversations with my young son about where meat comes from, and the animal welfare consequences of eating it.
I feel the same way. I've hiked a few times at one of the locations in these photos with my 8 year old son (under close supervision). I think it's a great way to build a sense of responsibility and humility.
Unfortunately, that also makes it inherently more dangerous. Just a month ago, three tourists went missing at that location. [1]
Apropos mixing bitterants, it's quite common to apply a bitter nail varnish to help people stop biting their nails. Not an addictive substance, but an addictive behavior.