I took it to prevent people from going to Talos and learning their vast powers. Not to prevent the Talosians from doing anything.
"KEEPER: Your race would learn our power of illusion and destroy itself, too."
That's the Talosian argument. And Starfleet would see the Talosians as the villains, so it isn't likely they would listen to their argument... Rather, they'd suspect the worst.
I love the twisted morality at times in Trek. "We won't kill a criminal, but if a random disease or geological disaster strikes... well screw those billions of people, it's not ethical to help them."
The TOS folks never let billions die, while the TNG folks never cured any criminals...