I think that's what the main issue is when we say music has gone down hill over the past 30 years. It used to be common to have a line that was full of clear, distinct phrases that formed a melodic groove but over time the idea of using a computer to play root - fifth as a foundation for other things has really dumbed bass lines down to nothing. Nirvana's "Come As You Are" is a prime example not only because it's so simple but because it just repeats so often that it's reduced to nothing but mindless foundation for other instruments to play over. With the advent of drum machines, are the drummers next? 30 years from now will brilliant pickups from drummers be a thing of the past? Look at the lines to "Sitting on a dock of the bay", "What's Going On", "Darling Dear", "For Once in My Life" and, to a lessor extent, "Signed Sealed Delivered" and "Superstition". Every one of those has parts that sound out clear phrases that make sense and form ideas. Personally, I'm convinced that the lack of those phrases and ideas are what's dumbed popular music down to the point that it's gone stupid. Simple can be good... "Dock of the Bay" is nice and simple, and it yet it flows beautifully. But without feeling, voicing, intonation, phrases and ideas, what do you need a bassist for? A computer can play root-fifth. If a computer did that then the result would be uninspiring, lifeless and dead... Much like today's popular music.