I know more than one full-time professional bassist with a SUB in the arsenal.
The SUB hits a certain price point that Stingrays and Sterlings will not hit, generally not even in the used market unless the Sterling/Stingray has been particularly abused. A used Stingray/Sterling is a great deal at 700 and a good deal at 800-850. This young man paid $574 dollars and has a brand new made-in-the-USA bass with factory warranty and no one else's gunk on the fingerboard. And - oh yeah: it's a Musicman.
That's hard to beat, ain't it? Of course it is. Those of us with more money are still going to pay the higher (and yet still reasonable) prices for our Sterlings, our Stingrays and our Bongos. But the SUB gives everyone a chance to get Musicman quality, to get their foot in the door, as it were...and I would imagine that those happy SUB owners, when they decide to change or upgrade or add to their burgeoning collection of bass instruments, will consider the quality and value they got from their less expensive Musicman bass and say, "Hmm, I think I'll have a Stingray!"
Or, of course, a Bongo or a Sterling. These EBMM guys.....they ain't dumb, eh?
Now I admit that I had a bit of a twinge when I started seeing the OLP stuff. It is an awful lot like being a Fender owner when the Squiers started hitting the market (and yes, I was around even way back then, when pterodactyls darkened the skies). But again, if my argument holds true for the SUB, and I think it does, isn't it exactly the same thing for the OLP owners? Not too many serious players are buying OLPs. It really is, moreso than the SUB, an entry-level bass. Many OLPs will be played for a few months and then either wind up on eBay or stuck in a closet while the purchases moves on to a new hobby. Bass playing was just not for him/her. It happens. But out of all those entry-level buyers, a certain percentage will fall in love with the instrument itself and decide to move UP rather than out. If the OLP appealed to them as an entry-level purchase, we already know they like the basic design of the MM basses, so - what will their step-up instrument be? If they have any sense - and if the OLP did a decent job of meeting their beginners' needs - they'll most likely at least seriously consider a Stingray.
So next time you wanna be uppity about it, and I fight the urge myself from time to time, think about it from a marketing point of view. Crazy like a fox, these EBMM guys.