I think it depends on the person, cause remember some are rythym guitarists, some are lead, so that alone can affect the way the approach the bass. I started off playing guitar, and naturally since I couldnt blaze up the neck like of Page or Hendrix at first, I stuck to the main rythym and powerchords. Believe me, I sucked! I had a friend at school who needed a bassist for his band, I agreed to try it out, so when I picked up the bass, I took to it like a duck to water, it was so natural to me. But I've played with other musicians who were INCREDIBLE lead guitarists, but they played the ryhthm and grooves like they should have. They understood they are 2 different instruments. Im a huge Jack Bruce fan. He played a little rhytym guitar on the side, and what I love about his bass playing so much is that he played melodies and leads on the bass instead of doing the stripped down, bare minimum. So again, I think it just depends on the player.