Things can fork as much as it wants: Any alt-coin that becomes successful will attract people trying build businesses around it.
If you want to prevent people from making money on it, find a means for people to achieve their goals without exchanging anything that can be converted into money. Good luck trying to do that without also making it pointless and/or unusable.
Happy that Bitstamp isn't US owned but not sure for how long. It's basically a repeat of what happened with the Internet. No one is stopping other regions from taking their own slice of the pie. It just appears that Americans are quicker on the innovation front and seem to understand where future value may lie and thus take appropriate risks.
The two biggest Bitcoin exchanges by far, outside China, are Mt Gox ( Japan ) and Bitstamp ( Slovenia ).
Coinbase is a little later to the game...