That's very far from the truth. If TC was frequently accepting and then breaking embargos, then very quickly their sources of embargos would dry up.

TC very clearly announced to everyone that they no longer were going to accept unsolicited embargos. Their motive was that many of their competitors were breaking embargos by a few hours and then claiming it was accidental. The competitors that were breaking the embargo weren't being reprimanded by the PR firms, etc. at all. There was a clear advantage to breaking the embargo (more traffic, better ranking on news aggregators, etc.) and those who played fairly, like TC, were essentially being punished for it.