When people say that an advantage of Bitcoin is that it is a currency not controlled by a government, they do not mean that governments prevent them from spending their dollars, or that governments are aware of what their dollars are spent on. If that was what they meant, you would be right to say, "Those two are the exact same goal." But that isn't what they mean, and so you are mistaken.
What people actually mean when they say "not controlled by a government" is that the dollar has lost 98.3% of its value since its peak in 1792–1833. It fell 6.3% in 1834, but stayed at that value (with occasional deviations downwards) until 1932. From 1932 to 1970, it lost 47% of its value, mostly in 1933. In 1971, it became a fiat currency, and fiat currencies are famously prone to inflation; since 1970, the dollar has lost 96.6% of its remaining value.
I'm measuring the dollar against gold here, not just because gold was what defined its value from 1792 to 1970 (and part of 1971), but because gold was the standard of value for international commerce from sometime around 100 BCE until 1971. You could reasonably use a different good as the standard of value, and you'll probably get marginally different results, although a few goods (passenger pigeons, 32-bit multiplications, warships) will give you significantly different results. Gold is relatively convenient for this because of the wide availability and verifiability of its price. Gold's short-term volatility makes it useless for very short-term comparisons, though, by which I mean anything less than 10 years.
When Bitcoin people say they want a "currency not controlled by a government", they mean that they don't want 97% of their savings to evaporate in a mere 50 years because the government decided that printing money was a good way to meet its payroll and pay its bonds.
As fiat currencies go, dollars are actually doing pretty well. Here in Argentina, our peso has lost about 25% of its value each year for the last several years, but this year, it's accelerated; it's lost 50% of its value since April. (It's worth 5¢ today, down from 10¢ in April.) And of course everyone remembers Zimbabwe's hundred-trillion-dollar bills.
Now, you could argue that 5% inflation per year doesn't really impair a currency's use as a measure of value or a medium of exchange, only as a store of value. And you might be right. But there are a bunch of people out there who would love to have a secure store of value that they can also spend, which is why the dollar price of gold more than tripled in 2005–2012. (It's recovered a bit since then.)
I am not going to take a position here on whether providing a potentially safer store of value than dollars is a good thing or a bad thing. It's a thing some people want, and you might not want them to have it. That's okay. I'm just pointing out that they want it, and it's not the same thing as money laundering.
(Historical gold price data from http://onlygold.com/m/Prices/Prices200Years.asp.)