People don't want the government or anyone else knowing what they are buying, selling or transferring around. They want true virtual cash.
This is very true, though only effective if the anon crypto-currency doesnt leave the system.. as soon as you buy something, esp a physical good.. it kinda has to ship to your addr. As such, there will be a paper trail. Same with exchanging crypto to USD for example.. it gets wired to your bank etc. Perhaps the resourceful individual can get around these constrainsts but for the meantime, tech protects privacy and is well and good, but true, absolute anonymity is an illusion.