It is irrelevent to it’s use factor. It may indeed be widely used as a legitimate laundering mechanism but thats besides the point. As far as economic discussion is concerned, determining exchange ratio’s and analyzing historical exchange ratio’s (Prices) it becomes very relevant whether BTC is a money or not. You would be mis-informing people, in fact frauding them, if you lied to them and told them that BTC’s had a historical exchange ratio establishing todays stable prices(which it does not).