It appears that the 'consensus' from this thread is that the bicycle isn't a particularly reliable means of transportation, hence the need for multiple bicycles...

After all, most folks only have a single car (multiple car households usually have multiple drivers) per person, so that must mean cars are inherently more reliable?

Or could it simply mean that those who espouse the N+1 approach are simply expressing their innate need to consume resources and bikes are a particularly affordable resource for the general public?