Probably it's just the business models that have grown up in different parts of the world.
From an engineering standpoint, integrated system design is absolutely to be preferred. On the other hand it means that a single designer has to be equally good at speaker design as with digital, mixed signal, and analog. Taking Burmester as an example, their speakers get quite different reviews from their electronics.
It would also be interesting to know how many buyers, European or American, actually buy a complete system from one manufacturer.
From an engineering standpoint, integrated system design is absolutely to be preferred. On the other hand it means that a single designer has to be equally good at speaker design as with digital, mixed signal, and analog. Taking Burmester as an example, their speakers get quite different reviews from their electronics.
It would also be interesting to know how many buyers, European or American, actually buy a complete system from one manufacturer.