Person A: one who gives Bitcoins in exchange for Widgets.
Person B: one who gives Widgets in exchange for Bitcoins.
Notice the symmetry. The name buyer and seller are arbitrary designations depending on what you consider the currency and what you consider the good being sold.
The inflation/deflation symmetry exists but it is not in the same terms. Deflation for bitcoins is the same as inflation for widgets. The widget holders are desperate to trade their widgets for bitcoins since their widgets's purchasing power is decreasing, but bitcoin holders are reluctant to buy widgets since their value is decreasing.
Isn't deflation for the buyer seen as inflation for the seller and vice versa?
Why would you then not (applying your deflationary spiral model) expect a "market death" from sellers not selling under currency inflation?