> If I buy an asset that only appreciates at the rate of inflation, then I end up paying taxes on what amounts to a fake gain. Even if it appreciates faster my effective tax rate is higher than the actual number used to calculate my taxes.

The same is true of getting a raise and paying higher taxes on a "fake gain" (i.e., your effective tax rate slowly rises as each boundary shifts lower in real terms). That being said, I guess my main complaint wasn't with the inflation claim but rather with the idea that the risk/return line is somehow relevant to taxation.

What you are describing is different from what I'm talking about. You are talking about how tax rates can go up over time if the brackets are not adjusted for inflation.

What I'm talking about is the fact that you can have a nominal gain that you pay taxes on that is not a real (inflation adjusted) gain at all.

These are two different problems. The first we handle by adjusting the tax brackets every year. The second we do not handle. I suppose we could, but it would be a lot more complicated.