The Boeing of today is merely a husk of its former glory. If the U.S. had another viable domestic airplane manufacturer I bet we’d see a lot more pressure on them. That can still happen. I hope it does.
The commercial aircraft part of McD was dead when the merger happened. The had a cash cow called the "MD-80", which was a derivative DC-9. That had stopped selling.
Boeing got more value out of the defense part of McD.