Interesting rant you have there....especially as one of your "fave bassists" could easily be tagged with the title of "a bassist that pushed boundries"....a certain Mr James Jamerson. His bass lines were (and still are) revered as something that made others take notice of the bass as an instrument in its own right. An instrument that could have its own voice and could play melodies within a song.....just like a lead guitarist and other instruments do.
One of the many bass roles is to keep it all together. Sometimes this requires leading from the front, sometimes more of an accompanying role. I'm lucky that in my band I play a wide range of music that encompasses root / fifth lines along with busy, fast lines that define a track. I think its great that we still have people who are trying to push the boundries, just like Jamerson, Jaco etc. Not all of it is going to work, but maybe something interesting might come out of it.
If Jamerson hadn't "pushed" then we all would have missed out