It being a jerk move and it not being against the ToS are not mutually exclusive. Hunts, at least from how I know them, are a community effort. I'll spawn something today, someone else will spawn the next one tomorrow, and while we're each entitled to soloing the things without anyone else being there as far as the ToS is concerned, that's not how things ended up working. We have linkshells. We have hunting FCs. And while it originated from the need to have backup because you still need a large group to kill on-level S ranks, and even A ranks, if you're already in that kind of social interaction, it's only logical you'll let people know even if you don't need their help in order to actually kill the thing. Because tomorrow you'll want them calling it out so that you can partake of what they found/spawned, too.

Against the ToS to play the lone wolf? No.
Jerk move regardless? Absolutely, even if I agree that a line should be drawn and if you have 50 people on-site, you shouldn't have to wait for that 51st who was too busy finishing their craft to teleport over. But that's its own can of worms of a debate.

Also, they can say 'that's not how it was intended' all they want, that's just burying their heads in the sand and willingly ignoring how things ended up working. Not to mention... how on Earth do they think people ever got the tiger? Hunting alone? Please.