The reason for Boeing's recent failures are actually well known: They purchased McDonnel Douglass and became defense contractors.

When they did that all of the McDonnel Douglass execs they acquired were able climb up the ranks of Boeing because they had political connections to get those DoD contracts. The story is the Boeing corporation acquired McDD but McDD execs acquired Boeing.

What happened next is Boeing started doing normal DoD contractor practices and outsource as much as possible to cut costs and open new non-union shops. The clusterfuck that is Boeing now is the outcome of that process.

Obviously you can still call this "c-suite greed" but that would be missing some important details.