Simple. You guys are all long. Why would they hand you a profit?
If you were short, they could hurt you, like they did back in September.
While defending a peg by selling your own currency is easier than having to buy your own currency and running the risk of depleting your limited fores reserves, it is not without risk.
The SNB lost billions when trying to unofficial pegging EUR/CHF around 1.50 back in 2009. And they stand to lose billions more if they fail at 1.2000.
