Your scenario doesn't handle the case a market order does, i.e. close my position now. In a fast moving market, using limit orders for stops or exits is just going to result in partial fills or failed orders. If I want out, I want out, I don't only want out if I lose between X and Y, I want out period; that's what market orders are for, for that convenience, you accept slippage as a reality.
> There, that wasn't so hard now was it?
No, it's easy to do things that don't work, I can pump my order into /dev/null, that's easy too, and it's just as useful as a limit order for stops.