It's an animal, not a human. Animals have been slaughtered by the billions since humans figured out how to get more leverage with a piece of wood.
How is this any different than fishing ?
How is this any different than beating your pet cat or dog to death and selling their fur for my living?!
As a youth and for Summer recreation, I sometimes work for cattle ranches. I know about "slaughter", I've seen it. Having spent summers as a kid, protecting cattle from all sorts of dangers, I have watched them loaded into a truck that I know is headed to a feed lot, and after that, to a slaughter house. The contradiction is not lost on my reason or conscience. I know a quite a few cowboys that would not send their cattle to slaughter if they won a small lottery or inheritance. Enough to pay their bills and send their kids to school. But these cattle go to feed those that raised them, or to those willing to pay for the meat they eat. Cattle are not raised for vanity.
The seals that are bludgeoned to death, so as not to flaw the fur with a bullet hole, are not necessary to the physical survival of others. Economic survival, yes, but in a smarmy and parasitic manner made acceptable by the goods being sold in fine department stores. A butcher shop gives no pretext to the process of how it obtains its wares. The seals pelt is totally for vanity, the club for increased profit. Once the seals are gone, who shall they club next? Maybe your skin would make a fine lampshade (with apologies to the Holocaust). After all, the difference is only by degree? Why would you object? It won't hurt. You won't know what hit you.
Winston Churchill once remarked at a dinner, while pondering a chicken breast, "that someday, chicken breasts will be able to be produced without having to make the whole chicken". I look forward to that day, as well as the day that beef can be safely produced without having to grow the whole steer.
BTW, Yes, I do hunt. Deer, Elk and birds. And no, if you got within 10ft. of my horse with a club in your hand, you (or anyone else) would not walk away. Do I make myself clear?!