Presently, you can't really buy things you "need" with Bitcoin. Ask a landlord if you can pay your rent in BTC or a bank if you can pay your mortgage with it. Take your Bitcoin wallet to the grocery store and try to check out with it. You'll get blank stares at best.
On the other hand, you can buy things like iPads with BTC. The Bitcoin economy is not an economy of essential items right now, and this is largely because even if it were possible to pay for essential items in BTC it would still be just as easy if not easier to do so using some sort of fiat money.
The whole philosophical justification for Bitcoin is fine, and I am on board with that. But the present price dynamics of Bitcoin are directly undermining its viability as a currency and the philosophical motivations that support it. Satoshi was frustrated with the destabilizing monetary policy of the Fed, but having rampant price speculation due to an inherently depreciating currency isn't any better.