Boeing probably is a case of too big to fail.
There have to be minimum two airliner manufacturers and essentially that's what we have now. All the talk about re engining the lovely 75 and building a new single aisle to crush Airbus is fantasy land because then AB would be able to deliver planes not quite as good but in two years not 8 and just like the US will support boeing for tis military side and 'the national interest' .EU?UK would support Airbus in that situation. Not that bad a thing either way because on the one hand no one wants monopoly pricing (except Google) but pax and regulators do not want cut throat competition in something like the Airline industry.
The problem is rampant greed also known as 21st century capitalism . These determined /psychotic CEOs with their , its just another company, shareholder value, monster un-earned bonusses should not be allowed within a million miles of serious companies that are integral to safety related or critical infrastructure industries. That also means of course that Wall Street has to have a serious look at itself because of the influence it has on their appointments -all comes back to greed again
Finally, nothing much will change until some of these issues are addressed and a few C level people get to find out what responsibility really means when they go to jail-thats not just a US thing the UK is just as bad (The Post Office saga for example/ Railways etc). So a duopoly in the airliner business isn't such a bad thing but until greed is squeezed out of the equation stories like the gradual collapse of Boeing will continue to happen,