Had it occurred to anyone that these aren't "signature" instruments in the way we typically use that term? It could just be that Marcus Miller is invested in getting quality instruments to people at a decent price and is happy to put his name on that endeavour as a whole?
That is, in fact, my understanding of the whole venture.
I wonder how many people are really just trying to hide their disdain for certain types of people, rather than specific names or the size of them.
I've bought "signature" products in the past with the names of people of whose music I wasn't particularly a fan. Not that I necessarily *disliked* their music, it just wasn't what I typically listen to. As I said earlier, I had a Jack DeJohnette cymbal, I had a Peter Erskine snare, Bill Bruford drumsticks, and probably others. All great musicians, but I didn't buy those products because of them, but because the specs fit my tastes.
Taylor Swift plays a Johnny Marr Jaguar. Is she a diehard fan of The Smiths? Or did she just find a guitar that she liked? I personally was a huge fan of The Smiths, but I wouldn't buy the guitar just because of his name, I'd buy it because he and I have similar notions about how a guitar should work. Heck, I'd be more likely to buy it if Fender reissued it as the Taylor Swift Signature Model.
There are probably some musicians whose names I would find off-putting on an instrument, people with really objectionable views or past histories, I suppose, but I can't think of any off the top of my head.