When the hashing power has decreased and rigs were sold. But yeah people are in denial, that's what gives scam artists alternate cryptocurrencies a free hand.
Deepbit disagrees with you. Over the past month the hash rate there (measured, not estimated) has gone from 5 terahash to 5.5 terahash. It was going up 50 gigahash a day as the price went below $10, and has since flatlined -- but it has not decreased in any measurable way.
*MY* remaining mining hardware is on craigslist, I don't deny it. Already sold two 5830s for $120 each, hoping for a difficulty drop or price pop to sell the last 2. But that won't be the general case until FPGA and ASIC miners make video cards as obsolete as CPUs.
Why do you people still believe there's going to be bitcoin ASICs? How many goddamn times does it have to be drilled into your head that the economics will NEVER work out enough to develop one until BTC are trading for well over $50/coin steadily...