Because: 1. I can't play drums and don't want to either. 2. I can play a wicked fingerstyle acoustic guitar in many weird tunings, but my electric playing sounds like 60's surf music. 3. I hate the sound of most digital keyboards and lugging around a Hammond B-3 with a Leslie seems a bit extreme. 4. Playing bass is fun and I always seem to meet really great lead guitar players to jam and gig with. What's more they tell me my playing gives them a good vibe for soloing. People always tell me how I seem to lock in with them well, etc. Therefore I play bass.