When I again saw the title of this thread, I was reminded of my years in the premium wine business. Particularly in France; in Bordeaux, more specifically, some labels command high prices because of a historic record of quality. Others because of scarcity - and a recognizable and well-marketed name. Some, on the other hand, trade on long-lost attributes from a prior ownership and management.

How many instrument makers are still in the hands of original owners? How many, once highly regarded, have disappeared? Martin has had its downs, but has a single family legacy of ownership and a very good track record of quality overall - and it is one of the oldest and best known producers of string instruments anywhere.
In the end, people will always be willing to pay a bit more for what they perceive is a higher level of quality.

In the end, it's a love affair. As we all know, they don't always make sense to others. They don't have to.