That's a rather stupid reason for killing those dolphins.
However, I don't agree with the article. It says that dolphins shouldn't be killed because they're intelligent. Pigs are pretty intelligent as well. Yet we kill them on a much larger scale than dolphins. No-one seems to care much about that, because dolphins have an anatomy which happens to make it look like they're smiling and they're supposed to be all cuddly and stuff while pigs are dirty and ugly. I think more blood gets spilled in one butchery in a day than there is in the sea in that picture. And this event only takes place once a year.
/care