1) Wealth and money are not the same. Wealth produces buying power while money are simple bank notes which represent an IOU. The power is in the buying power.
2) BitAssets simulate the buying power of any asset, thus they are digital polymorphic market consensus assets. The consensus process is shaped by speculation which through incentives creates a peg to map near 1:1 on any asset.
3) Labels which measure are money but if it is a label with nothing backing it then it's worthless value because the value are not the labels/digits. All BitAssets are actually backed by BTSX. Think of it like grains of sand on a beach and you add water to those grains of sand to make sand castles. Those sand castles look like indistinguishable simulations of real castles and because those grains of sand have a non 0 value to them the only thing which changes is the amount of sand/water used.
BTSX are shapeless abstract grains of sand. They are like atoms in the universe and aren't solid but can form any structure. The amount of them you need to form the structure is always changing but you don't really care as long as you get $1 buying power worth of sand. So the peg holds the shape of the structure to guarantee you $1 worth of BTSX no matter what the market does.
This is actually an incredible new capability that humans never had before. Now you can simulate the buying power of anything and do it completely decentralized. As long as people need to make money to live they will speculate and there are plenty of capitalists on the planet who wouldn't mind.
Eventually market bots will do all of that and the pegging will happen by artificial intelligence. For today if you're involved you've got the opportunity to live like a stock trader and make significant profits until the world figures out what you're doing.
Bitshares allows us to protect our purchasing power from economic vultures.https://en.wikipedia.org/wiki/Purchasing_power