Although you might not read music, you haven't ever been in a situation that required it. At some point in your playing career, you've probably been inspired by either a specific bassist, a particular band, or a type of music that you might not have much experience playing, yourself. The inspirational moments you may have experienced while listening to this player, band or music struck someplace inside you, and therefore moved you emotionally. For most of us, these moments are what motivate our creativity either directly through our own music or indirectly through other aspects of our lives. Unless our basses were just purchased to function as a dust collectors, I think we can all agree that we wouldn't mind being better players than we are now.
Inspiration yields the desire to improve.
Bass lessons, regardless of the medium in which they are taught, obviously provide a way to become more proficient with our craft. I wish I could play jazz, but I don't even understand how I would begin to learn it. Bass lessons can give you a sense of direction in your quest to overcome obstacles. Lacking the direction or focus we need to get there. I know that my knowledge of scales and arpeggios will help my improvisation, but I don't know what kinds of exercises I should practice to become proficient at them.