This is definitely part of it. People need to adjust to a new price reality, and while they think they want deflation they certainly do not want what a deflationary period entails is happening in the economy.
The Fed will fight across the board deflation like crazy because that's how the economy ends up in a depression.
We did have high inflation for a year, and were told it was temporary, before tools were deployed. Would a sustained period of deflation be met with a similarly lagged response?
My understanding (I am not an expert) is that tools for dealing with deflation are much less effectively deployable and have ripple effects that can significantly damage the real economy.