I totally agree with you. Been there done and seen that. If you cannot use these type of strategies to defend yourself in the jungle that corporate life is, you might be in the wrong place.
Sometimes it's not only helpful, but quite necessary to blame others for a project that went wrong, especially if you worked as part of a team in collaboration with another team. You have to put the blame on others not only to save your own ass, but also to defend your team's reputation, your colleagues will love you for that and, of course the opposite team will hate you (even more), but war, be it individual against individual or team against team is part of the corporate living.