I've had to go through this same technology discussion with egnineers about engineering intsruments. "SSL boards suck" or "Neve is the best" or "nobody builds better warmer boards than Cadac" or the "MCI digital sounds better than the Sony 3024". And everyone has a viable technical reason. But nobody talks about music. They just talk about the tone or color of specific pieces of the sonic chain.
Fair enough, there are all kinds of engineers including many crappy ones, but I'm observed similar behavior from musicians, not least around here. It's a lot easier to talk shop about gear than it is to put forth the work it takes to bring your own skills to the next level (not talking about anyone in particular). I'm not excusing those engineers, I'm saying that we're not any better as a class.
So I guess my point is stop stopping and start encouraging.
I can relate, but it still sounds like a bass player centric point of view. The other side of it is that the engineer's comment probably came about due to his past experiences, which would put it at an equally subjective level to what you are saying here.
From their perspective, too many musicians want themselves to be the loudest thing in the mix and to have their over the top effect laden fusion tone to be on the record regardless of style or whatever else might be more deserving of the listeners attention in the mix. Their job is to please the artist who is paying them and make a good sounding recording, and to be blunt, those goals are frequently at odds with what musicians on the date want for their own sounds, and this is not entirely unconnected to the fact that those guys are sidemen for somebody else's material and vision.
Ultimately the entire recording process exists to serve the recorded song. If the bass player is arguing that the engineer should be taking his sound as is because it's his sound, and the engineer is arguing that he needs the best possible sound for the recording no matter how much the bass player loves his usual sound, it is at least arguable that the engineer has the better sense of priorities.
There's no clear cut answer if you look at it as a territorial dispute, because clearly there is overlap. The bass player is producing a sound and the engineer/producer is capturing a version of it and will be subsequently modifying it to use it in a larger project which he is responsible for.
There is no such thing as just using the bass sound as is in a recording without changing it. It just doesn't work that way; all recordings are different sounds compared to the sources.