The current drop is Bitcoin price is probably due to the uncertainty that ASIC miners are creating not the actual ASIC miners themselves. People aren't sure what's going to happen - (especially the GPU Bitcoin miners) so they are likely selling pushing the price down. Once the adjustment period is over, price will likely rebound.
You're missing OP's point: ASICS don't bring uncertainty, the outcome is *certain.* If you had a money press that prints real money, why would you sell it?
Edit: ASICs are, or are claimed to be, these printing presses. If they make more bitcoins than you pay for them & the juice to run them -- a no-brainer win unless... THE VALUE OF BITCOINS GOES DOWN. That's the only sound reason to sell the printing press
And they're being made. And sold.