Some people just have a gut reaction to these sort of things. Is whaling inherently more evil or grotesque than murdering humans? Of course not. Is a whaling sim more evil than a game about killing people? No, I doubt anyone would actually argue that.
But just to help you out; replace whaling with something like, say…dog fighting. Do you think that would raise some eyebrows? Why? Is dog fighting somehow worse? Not really. But it hits a little closer to home. Nobody cares about games where you can send elephants into a line of spears or set pigs on fire just so they’ll disrupt ranks of soldiers (Rome:TW), because we’re so far removed from that now. But dog fighting is still a real thing, even in this country. That’s why it would cause outrage.
Besides, some people sympathize more with dogs than they do people. Some people feel the same with whales and whaling, which as noted above, is still a thing in some parts of the world. Or maybe they’re just desensitized because we’ve been portraying the killing of humans in games and other media for ages. We’ve glorified war for thousands of years.
I actually don’t think there’s anything wrong with whaling sims. It’s just another violent fantasy in a hobby built on violent fantasies. And, as I tried to hint at in my first post, it’s not exactly likely to lead many to take up the business of whaling.
But I do understand the psychology behind the outrage. I would expect a small minority to voice their opinions over something even as innocuous as Nantucket. Which is perfectly fine, of course.