Risk of ruin outweighs business model of modest and consistent gains. Ever tried to re-balance an options book that features short gamma in a moving market? You can't really even come close to covering with stops like cash equities or futures - you find the offers to be incredibly wide and thin, so you will sit with it, and after five minutes you wish you would have lifted what was there. You are dealing with a subset of a market with less volume - and markets makers, either on the floor or on the screen, are not there to get run over if they can help it. Exchange designations and orderly markets be damned, they are not going to give back eighteen months in two hours.
If you are still convinced that selling vol is the way to go, just shimmy on over to the energy and metals markets and sell ATM strangles to your heart's content. ICE OTC, Clearport, and LME physical ring for size. ICAP and Prebone-Yamane will find a market for you.