I think when Asobo said third party devs can do it better they were referring more to the amount of work that can be done. They can't make every plane out there but I agree with @domkle's post 100%. You just can't compare flight sim 3pds to the ability of a AAA level studio putting out projects nominated for game of the year. They have far more resources at their disposal, not to mention the fact that aircraft manufacturers are even more willing to work with them.
This is not a knock on 3PDs. In fact it's actually amazing what they've done over the years with what they have. But the line of thinking that says Asobo would need the same amount of time to make a PMDG level plane is straight up misguided.
The average DLC expansion for modern games cost about $30 and they often feel like stand-alone games. I'm fully confident Asobo could put out a top of the line 737 and charge far less than what PMDG will. Just look at the amount of work they've accomplished from concept to what we have now in a few years.