Where you're going wrong is thinking that OB, or any other synths, can only make one type of sound. Sure, there is a flavour in some of these OB sounds, maybe too much for some things depending on your taste.
but... there are lots of sounds you can get from these.
I maybe wouldn't get an OB-6, because the pads have too much flavour - but - I'd love an OB-6 to use for pads sometimes, bass, seq and lead sounds... Same with the various OB vsts if you ask me - except affordable to only use for a couple of types of sounds.