there will always be clients for the 600 no matter what the next size up simply because noobies don't need to start on that much bike and the smart ones won't hence the need for the 600. i am still fairly new being i have only ridden for about 2 years, i knew starting out with 1000 would be too much and the 750 would be too. noobs need the 600 to learn on!
but i see what you are saying.