Ultimately, I think one is a good bassist if what you are playing fits the given music appropriately.
If you are a playing bluegrass, that means hitting the 1-5 like a metronome. If you are a Dream Theater bassist, it means being able to arpeggiate an A13-flat9-dim2 chord, then invert it.
So the role of the bassist is dependent on the situation! I agree and have no clue why some players think otherwise.