A decoupling event will occur when two conditions are met:

The combination of these two peices will result in the rejection of Bitcoin as a more obvious blow to personal finances than is currently understood, but I believe that one without the other will not have the effect people might be expecting. I think right now we're in a time when people could be suffering from inflation or an economic callapse and still do whatever is neccesary to support the current system. Be it driving an obviously inconvient truck full of cash to buy bread, or begging politicians for more inflation in the case of a crash.