Excellent observations.I met Jaco, I wouldn't say I knew him. Plenty of my friends played with him. He was a troubled guy, clearly, and he acted out in ways that were self-destructive in the extreme. Whether you like or dislike the way he played, he absolutely expanded the possibilities for bass players. In that sense he was like Larry Graham or James Jamerson. Being a bass player will never be the same because they passed this way. It also has to be said that playing the way these guys do and did requires that the music they're playing be arranged to suit the bass playing. They were special cases, and I suspect that caused them much difficulty in their careers. The rest of us can't walk into a jingle session or a Broadway show and play like those guys - we'd get fired. But our playing can be informed by what they've done, and how we use that information makes each of us the unique players that we are.
The most important thing is to see someone like Jaco as a person, complex and flawed. If you see him as a monolith, an idol or a freak, you reduce him to a two-dimensional figure. That makes it impossible to understand how he got to where he was. The difference between normal musicians and real game-changing artists is their dedication and willingness to work much harder than any of the rest of us would. I have a friend who was Prince's engineer for a while. He said Prince was the hardest-working most disciplined guy he had ever seen. Jaco was the same, willing to work harder and practice longer, tolerate more discomfort and give up more of a normal life than the rest of us. That's why he was such an incredible player, not because he got hit by a bolt of inspiration from the blue.
I've always had the same feeling about him-- being bipolar, his highs were HIGH, and his energy level and vision at those times were incredible. But he also put in the work. For example, he learned all of the natural harmonics on the bass. The rest of us just used them to tune up, thinking, "I bet you could do something else with these things... oh well..." but he went ahead and made "Portrait of Tracy" out of them. He also told me that he played Charlie Parker LPs at 16 RPM (the old folks will know what I mean) to laboriously learn the heads and solos by ear. Finally, he also told me that when he was young and playing country club gigs (he cited "Proud Mary" as a typical tune), he would spend the entire night fingering with only his ring finger, to strengthen it. He was prone to hyperbole at times, but in this case I tend to believe him. How many other people would do that?