No one is saying that. They are saying it's not betting on flat price. All trades by default want value to move in their direction. Flat price is one dimensional. Spreads are multi-dimensional. They have far more combinations and permutations in which to profit.
of course, did not read the entire thread closely. i feel there is added edge trading this way over binary bets; but without good models, edge, time..it's all gonna suck. i have never talked to bone, but i do agree with most of what he posts on spreading.
It doesn't really matter how or what you trade as long is it is consistent for you. Be it far from me to argue with anyone's success. Of course there are plenty of successful directional outright traders. I also believe that the continued evolution of HFT has made markets more turbulent for a number of manual day traders. And of course, I am biased personally towards spread trading and arbitrage and correlation-based strategies. No secret there. If you are a dedicated scalper, it is likely that you can only ply your craft to one or two markets - the focus and energy pretty much demands it. I have not met very many scalpers who could successfully do it across a number of markets during the course of a day. It's no mystery that most of my clients are successful scalpers who want an additional revenue stream and some flexibility in their chosen profession. One of revelations to them is the shear number of possible combinations and permutations available to them in terms of spread combinations. You can literally build your own markets in terms of volatility, trading range, and price action behaviors. You simply do not have to ransom yourself to one or two markets and suffer through the choppiness and turbulence.