There's no contradiction. The prices in BTC for services/goods are lowered until people want to pay. With speculation, the trick is that eventually the currency

There's no contradiction. The prices in BTC for services/goods are lowered until people want to pay. With speculation, the trick is that eventually the currency has to land in the pockets of someone who will trade it for services/goods. If no one wants to do that, you basically have an infinite loop for currency speculation going on and eventually there's no point in grabbing the currency when no one wants to give it up unless it's for USD.