What kind of company or culture is that, when someone asks for help from a group and no one volunteers to even suggest to them a person that would be the best candidate to help them?

I've never been at such a company and I hope I never will.

Sometimes the person who knew how to make it all work has left. Such is the plight of the maintenance programmer.

True, but if the person who knows that code leaves, it's the manager's job to designate someone else to be responsible for that code.

Bystander effect in a situation that is not critical is a good sign that your company culture is fucked up. That's also on management.