The idea is that if it only ever increased in value, no one wants to part with it, thus it ends up becoming worthless.
I have found in the past that I had no problem spending fiat on crap that I didn't really want or even need. That is how the government wants it to be so they can make us into zombie consumers that feed them with taxes. Now with Bitcoin I really have to want it to even begin to think about spending, and about half of the time I still do not spend. Bitcoin has changed my whole attitude about saving and investing money.
