I'm not too sure what institutionalized and socialized guilt means. Sounds pretty unpleasant. Of course there is collective wrongdoing, such as promoting or colluding in social injustice of one sort or another.

Individual remorse for doing actual harm isn't really sufficient, if it doesn't lead us to try to do what we can to undue the harm, or balance it in some way.

What's important isn't that people should feel guilty, it's that they accept responsibility for their actions.