I don't buy into the "conditioning" argument. That takes away any sort of thought process and implies that those of us who bought Fenders didn't do so of their own free will but because we're under some mass hypnosis. The reason people buy Fenders is because they sound freaking great every time in any situation.
It's an interesting question. I see it the same way as you, that a Fender just has a great sound plugged in. Great because we are used to that sound? Who knows. There were a lot of non-Fenders on 1960's recordings. There has to be a reason why Fenders triumphed over Gibson, Rickenbacker and others. (And I say that as a Ric lover).
Did the Fender / Ampeg combination become famous because it was lucky to be on some great records, or was it part of what made those records great? For example the Beatles had a modicum of commercial success, but I see few people other than Beatles tribute bands lusting after Hofner / Vox combinations, even those of us who admire McCartney's lines.
An Ibanez is a beautiful bass, and I've heard them get some really nice sounds. I would say they were really more versatile than Fenders and then I watch a clip like this one.....
Guy Pratt's great disco bass lines - YouTube
