People have though about it.  It has been discussed many times here.

There are people who are concerned that a deflationary currency cannot survive due to the incentive for hoarding.  Those people choose to either not use bitcoin at all or to attempt to time the market and jump out just before it crashes.

There are others who believe that there will always be a need to spend bitcoins, and as such hoarding will not present a problem.  Those people continue to use bitcoin as a currency comfortable in their belief that it will endure.

Only time will tell us who is right.  It will be fun to watch and see, yes?