I don't like to see creatures killed for no reason.
I understand that sentiment. However this isn't Bambi we're discussing and it's not something to trifle with, either. This critter is not only a meat eating predator, it routinely battles one of the biggest of the toothed whales (Sperm) and I'm certain it wins at least some of the time. The novels of Peter Benchley notwithstanding, there have been reports from various parts of the world of these critters attacking men. Unsubstantiated? Maybe. But it behooves us as the top of the food chain, to keep an EYE on the up and comers. If this were wholesale slaughter, I'd have to agree with you. But I kinda doubt killing one of these or heck a dozen is going to put a crimp in the population.
For hundreds of years, this was largely a mythical creature. Sea stories and wild tales passed down thru the ages until it became the stuff of Jules Verne stories. Like BigFoot, this was one that was only going to be settled with a body. A dead body. By all accounts this was a small example of the species. Had this been one of the BIG BOYS of legend, it's possible the encounter between man and beast could have gone the other way. I kinda doubt this was like shooting fish in a barrel. So don't feel too bad.