Some people wanna emulate da man, you know, Slash himself. So they subconciously fall into the trap that having a Les Paul and now this amp will give them the edge to be 'that much closer' to playing, sounding and emulating Slash. That's the purpose of a LOT of signature gear. Fact is, as I am certain many of us here have realized time and time again, new gear doesn't make us new players. Great gear doesn't make us great players. Oh, sure sure, it's about 'tone', that's the 'rationale' behind a lot of these siggy gear sales, it's about quality and workmanship and blah blah blah...
No. It's marketing. And when the penny drops and cats realize the amp still makes the mistakes sound just as loud and just as apparent, the magic disappears, and the mojo is gone. Resale.
Peace,
Mo