I think the biggest benefit of buying brands like Magico and/or Wilson is that when the time comes to get rid of them, they still have "some" value.
My point exactly. One can feel all warm and cozy that their direct-sale speakears didn't lose value, but then, nobody wants them used anyway, since they can be bought new so easily.
And Priaptor, I don't think the model itself is wrong, or not viable. Most people's rooms are also "mediocre", yet that's where the products will likely land. Having a fancy, acoustically treated room at the factory (or a dealer) is not going to help you determine what the product can or cannot do, in your house.
Partnering gear is another factor. A dealer with a wide assortment of product will be able to demonstrate how product X partners with product Y. And if you have your own particular choice in, say, amplifiers, you can always bring them to the dealer, or schedule an audition in your house, with your gear.
Sure, it can come out cheaper, in the end, to just buy blindly, and sell at a loss if the gear you bought is not to your liking (or not compatible with the rest of your gear). This is the same that happened with record stores, when CDs came out, and Internet popularised. It was just easier to buy them off the internet (assuming you're actually buying them not just downloading), blindly, and sell them back if you don't like them. What happened then? CD stores closed. Now with vinyl, people are seeing the value of actually going to a store, seeing the wide assortment in person, getting advice from the staff (or friends). So, it's the same thing, people who don't see the value in that whole interaction, will buy direct, every time. But fortunately, there are still some of us that DO value what a dealer (or record store) provides. The fact that some dealers are "mediocre", like you said, happens also with record stores (see Michael Fremer's RCD story), but in every business category, there's good and there's bad.
alexandre