Well I know that when Idung went down after the RS update on October 4th, it was down for 2-3 days for most people and people were going NUTS. They had no idea what to do with themselves without being able to bot dungeoneering lol. So I am trying to imagine if suddenly all bots stopped working... I think it would be complete and utter chaos in the Runescape cheating community for weeks, people would quit, goldfarmers wouldn't know what to do and would start whipping the chinese kids working in the factories so that they would goldfarm legitimately, and half of RS would fall apart. I am only slightly kidding here lol.
As for what I would do - I would probably continue to play for a bit legit and see where the game went. If it turned back into that old 2004/2005 community that it used to be, and the game actually became fun again, I would probably continue to play legitimately on my main and enjoy RS without all the bots hogging all the cash and crowding training spots. However, if the game totally died or too many people quit, I would most likely just sell of my RS gold and accounts, and try to make whatever cash I could out of the game before I walked away again. Lets hope it doesn't come to that though... I am just getting started in the world of botting and personally, I love it!