A deflationary spiral is bad not because it would lead to economic collapse, but because it means people are starving to death waiting for the price of food to go down. But it turns out that people are willing to buy things they need anyway, even if prices are constantly dropping. Look at computer sales, for example. You'd be crazy to buy a computer today - if you wait a year or so you can buy the exact same model for half the price. Yet people still buy computers. As long as people have a need or desire to buy things now rather than later, a deflationary spiral is impossible.
The great depression would like to have a word with you.
The Great Depression was mostly caused by a banking panic when the Fed stopped lending money to insolvent banks. The resulting bank runs caused around a third of all banks in the U.S. to go bankrupt, and the loss of liquidity caused massive deflation. There was never a deflationary spiral, and the deflation was a result, not a cause, of the depression.
