You got a point there Vegaas, but it depends on the person. You've probably never heard of em because your scope of music is limited.

There was innovative bass before the 80's, and bass does exist outside of rock & roll and jazz.
I'm in my 30's and I love many styles of music so it's easier to for me to know the guys I mentioned. There's plenty of people out there who have no clue who Steve Harris or Geezer Butler are and don't care to ever listen to Iron Maiden or Black Sabbath. Doesn't mean that people who listen to Heavy Metal don't love em. I can also verify there are tons of people who never heard of Wooten or Manring or heard their playing. But, I am sure plenty of people have heard the guys I mentioned on a CD, radio, or TV whether they knew it or not.
The guys I have mentioned do have technical mastery and redefined their instrument as well as their genre. They have displayed amazing flexibility. As far as transcending their style, well Butler only played heavy metal with one band. Same goes with Steve Harris, same goes for Flea. The guys I mentioned play BASS, not necessarily a genre of music or music for a particular band. Don't get me wrong, I love Steve Harris. Even though I don't play Metal anymore, he has influenced my playing.
When I was younger, I thought Billy Sheehan and Stu Hamm to be "legends". They have increibly sick chops and were well known in their day, but I don't hear much about them now. They haven't permeated people's everyday lives in the way that James Jamerson or Paul McCartney has.
Just to educate the young uns.
Larry Graham was the bassist for Sly and the Family Stone. He basically invented slap bass.
Donald Duck Dunn played on all the hit songs from Stax Records in Memphis. He was part of the house band called Booker T and the MGs. Aretha Franklin, Otis Redding, Wilson Pickett, Sam & Dave, and many others used him as the bassist. He helped define Memphis soul and R&B of the 60's & early 70's. When the Beatles met Dunn's band, Booker T and the MGs, they got on their knees and bowed.
Robbie Shakespeare was the bass player and part of the producing team of Sly and Robbie. They defined Reggae and Ska, and played on many of the Reggae hits from Jamaica from legendary artists like Black Uhuru, the Wailers, Peter Tosh, and more. So for you Ska kids, thank Sly and Robbie for helping to form the music you love.
Jerry Jemmott played with various Jazz/Blues/R&B musicians such as BB King, George Benson, King Curtis, and many more.
Link Removed Jaco once said "I'm just a poor imitator of Jerry Jemmott"
Leland Sklar has played with so many artists and is a key player in Nashville. He is one of the most recorded and sought after bassists in the country and pop world playing for people such as Linda Ronstadt, James Taylor, Hall & Oates, Jackson Browne, Phil Collins, Clint Black, Reba McEntire, and George Strait just to name a few. He's also on many soundtracks.
George Porter played with the Meters, the house band for Crescent City studios. He's helped shaped the modern New Orleans style music and funk. He's the most obscure because people in the Big Easy support their local scene so much, they never had to leave. But if you like the modern New Orleans sound, you gotta love the Meters.
To me a legend is someone who makes a great and lasting impact. Not just on the bass playing public, but on the general public. Also a bass legend makes other musicians legendary. Don't take it the wrong way, but if you want to define a legend, you should expand your scope of music. Then you will find true legends.
just my $0.02