I agree with all that. Yes, the only reason that gold is a stable investment is because of its large, mature market.
My point is that time will naturally take care of this for Bitcoin: volatility will reduce as its use around the world increases. And since Bitcoin has already proven it could survive its first 4 years where volatility was at its highest, then it is likely to continue to survive and grow without a monetary policy. Boostrapping Bitcoin was the hardest part, and this was accomplished successfully.
One last thing to remember. Even with gold's predictability and high price (assuming the US doesn't dump its cache on the market at some point) the US decided in the early 70's it wasn't secure enough of a product to base the US currency on. Bitcoin is significantly less stable then gold by a factor of thousands, and that's not even including its susceptibility to hacking (or, more precisely, to hacking its marketplaces). Bitcoin is also to small to ever have the amount of liquidity necessary to assuage the rest of the financial markets. Again, the issue with Bitcoin isn't internal. The issue is with it being strong enough economically to not scare off the rest of the world's financial system.