The reason I ask is that these tools seem to excel in helping to write new code. In my experience I think there is an upper limit to the amount of code a single developer can maintain. Eventually you can't keep everything in your head, so maintaining it becomes more effort as you need to stop to familiarize yourself with something.
If these tools help to write more code, but do not assist with maintainance, I wonder if we're going to see masses of new code written really quickly, and then everything grinds to a halt, because no one has an intimate understanding of what was written?