Artist endorsements have always been a lot more about image than they have about use. Clarinet players have seen this for over a hundred years, as first Selmer, then Buffet, and then Selmer have cycled through the "Leading performers" business.
(Heavy advertising and product placement is nothing new. In the Benny Goodman Story, there is a plug for Selmer, this in a movie that dates back to the late 1940's or so. It's during the scene where young Benny is arriving at his teacher's studio just as another student is leaving, and the other student observes "New clarinet, huh?". Benny replies "Yeah." Then the other student says "Selmer, right?")
When my son was playing semi-pro hockey (Junior A, for those who know the scheme), he was shocked to see how many players in the professional leagues were endorsing one firm's products but actually using another's. The sticks were not the major offender (sticks are now sold by a player's "favorite configuration" rather than by the old numbered "lay" system), but gloves, skates and other equipment was commonly advertised as being used by so and so, but not actually used by them.)
And, just as in hockey a good player can work wonders with minimal investment in equipment, so too can a good player with an adequate horn turn out some wonderful music. After all, 90% if not more of what goes into making music occurs north of the mouthpiece and reed.
As for what it's worth, you have to consider that a good product, no matter how good it is, is relatively worthless unless someone knows that you have it for sale. There are few people who are going to invest the kind of time and treasure in tooling and production facilities to make something as complicated as a saxophone without some assurance that they will receive a return on that investment (ROI, in finance wonk speak).
That's part of the reason for the "stenciling" which goes way back to the 1800's. Folks like Colonel Conn put together the equipment (the most expensive part back then) and the skilled labor (dirt cheap, even when unionized) and then pushed them to produce enough product to pay their nut plus a little left over besides.
When a musical instrument sales operation looked to add an item to their line, they might (if big enough) go into the manufacturing end of things for that product. But, as we see many times in clarinet and saxophone production, it's a snap to purchase a lot or two of instruments from (insert name of foreign production musical instruments on the low end here), stamp a different name on it, run up an ad or two, and go to town.
There will always be "boutique" makers who will (for all intents and purposes) hand make their horns. They are always small concerns, and they have to charge an arm and a leg for the handmade quality. If they increase the demand for their product, ultimately that hand made quality will suffer. An inescapable dynamic of the market place.