I think both you and the sibling poster, quibblings about "pseudonymous" aside, both make the same mistake "Hypothetical Nakamoto" make, namely a failure to understand what privacy means when the Internet gets involved.
Transactions in Bitcoindom are logged, and effectively logged eternally (how easily this can scale is open to question, Bitcoin's advocates argue the blockchain can be truncated at some point, but it isn't right now and I suspect there's a lot of agreement that will have to go on to make that happen.) The logging is public - anyone can read it. From the Blockchain, you - and everyone else - can determine every single transaction that's affected a specific coin or a specific wallet. To actively isolate transactions from a wallet you'd have to do an enormous amount of work and receive help from a third party that's laundering transactions for so many people it's close to impossible to link them, and, of course, that third party would know what you're up to.
Does this mean you can tell that "squiggleslash" spent 0.1BTC on coke, hookers, and gambling last week? That depends. Without the laundering service, it's relatively easy to tell that someone who's your customer (or your employee...) did that. And as more and more information leaks from you about you and your wallet, more and more information becomes available as to what you're doing.
By comparison, whenever Google logs what you're doing, most people here are up in arms. But the funny thing is that Google doesn't publish logs of every single browser's history to the Internet. It keeps that information to itself. So for most of us, Google invading our privacy means a handful of Google employees might be able to do the research.
The Blockchain, however, is public.