But isn't that true of any currency? Isn't that why a green piece of paper with Benjamin Franklin's face on it is worth anything at all, just because we believe in the US government's stability?
The US dollar is, like the existence of the US itself, supported by the collective belief of its citizens and quite a lot of people outside its borders. That belief carries quite a lot of weight because it's difficult to dislodge.
The reputation of bitcoin is shorter and less clear, and expectations vary.
Since taxes are done in the local government-issued fiat currency, local businesses need to hold some amount of that currency anyways. It is simpler and cheaper for local businesses to do all of their business in that currency not to mention it sidesteps the issue of dealing with currency risk.