Quote from science_trader:
It is not a directional bias. This is basic option's pricing. Option's price doesn't depend on people's perception of upside/downside probability. It only depends on people's perception of upside/downside risk.
Options wouldn't be useful if they were a bet on an underlying's direction. Options are useful and widely used just because they allow you to play the risk on an underlying. Options are a bet on volatility.
It violates the underlying distribution assumptions under basic option pricing. How would you propose to arbitrage the smile under such useful maths to make "basic option pricing inviolate?"
The deep ITM call or put buyer would disagree that options are a bet on vol over direction. The buyer of OTM street volatility[MSFT, INTC, PG...] are betting on gamma/vega. The OTM index call buyer is buying a directional bet, not vol.
OTM/ITM options(generically, across classes) are a gamma bet. OTM index puts are a vol or directional bet. <20d options have very little leverage to vega. Ppl trade them as a bet against the distribution and tend to deny the risk. I don't want to get into defining what makes a vega/gamma bet from a numerical basis, obviously there are exceptions and I realize options are priced in vol.

I sold some atm GOOG straddles for Sep... they're a vega bet into downside-gamma. Selling the outside 20d wings would make for a poor vega play.