The problem with outsourcing goes way beyond airlines.
As a customer, we trust a brand because they have built a good reputation. They then go and outsource to the lowest bidder. They get a cheaper product and when a plane with their name on the side crashes, they can deny responsibility.
As an employee, we want to work for a company with a good reputation. The company chooses to outsource their labor as an end run around labor organizing laws. Start a union, ask for better pay, and you get replaced my brand new employees at a different company.
If I buy a product, the company should back it up with employees on the payroll, not subcontractors. Unfortunately, greed overrules that pride in a product. I doubt outsourcing will ever change. Economically, it's the lowest cost solution. Now, if some laws were changed to limit/prohibit outsourcing of your core product, maybe. Laws could also be changed to assign liability to the outsourcing company. But I doubt either of those will happen either. One party wants to limit/eliminate organized labor and the other party barely pays lip service to unions.
As a final note, I'm actually surprised that some enterprising company hasn't started a passenger airline that is entirely subcontracted. I mean, you can't have scope if there is no contract. And you can't have a contract, if you don't employee any pilots to begin with.