Dark wallet anyone?
Explain to me how that helps you when you engage in a transaction that is a taxable event with an entity which reports those transactions.
Well most entities don't report transactions at the transaction level to the IRS. If that were the case then nobody would ever cheat on their taxes when it comes to cash transactions.
It would also mean that 99.999999999999999999999% (yes I know that is too many nines) of people wouldn't pretend they have no use tax due in states which "require" it.
Generally speaking only when an entity pays YOU do they report that to the IRS (most commonly in the form of W-2, or 1099). There are a few examples but they tend to be things which act as deductions for the reportee (student loan interest, property taxes paid, etc). For example if you buy a TV at best buy, there is nothing best buy reports to the IRS.
The reality is almost nobody is 100% compliant with the tax code either through wilful non-compliance (use tax is pretty common), errors due to the complexity, or ommissions the accuracy rate is essentially 0%. That being said I am not advocating people assume they can always cheat and not get caught but lets use some common sense. If you buy for a $20 domain name on namecheap with bitcoins and fail to record that as a capital gain there isn't much chance you are going to get "caught" (caught implies IRS would even be looking for that and they won't). By the letter of the tax law you should report it but if you don't it is very likely nothing will happen and if somehow you did get caught you could always argue good faith effort and simply pay the taxes due. Now on the other hand if you buy a bunch of Bitcoins at $0.01 each and now they are worth $40M and you plan to buy a yacht to "avoid taxes" well you probably should consult a CPA and there is a very high chance you will get caught and when you do you will be hit with fines and penalties.
I think the property classification is dubious, currency isn't property for tax purposes, neither are bearer instruments, stored value (gift cards), or even casino chips. On the other hand the idea that the IRS is going to demand records on all transactions (even ones where there is no legal requirement to keep records) in order to catch all the $1.38 in missing taxes on capital gains from spending bitcoins for a video game is kinda silly.