What I am saying is that you will get a better return just buying right now. Unless you already have a gaming machine, or are going to buy a machine for gaming as well. Then it is just free money until the power costs more than the bitcoins.
The growth rate of difficulty has been 4% a day for the last year, so yes, mining rigs have been less profitable than just buying bitcoins for the last year. If the network growth slows down to ~2.5% a year, then it starts making sense. The first year of bitcoin, the growth rate was almost flat, so you could make more money mining than buying bitcoins.
Keep in mind this is only about dedicated mining rigs. If you already have the equipment, there is nothing to lose by mining. At least for another 60 days when it reaches electricity costs.
Obviously, higher risks generally means greater chance at making it big but you also pose the risk of losing more, anything else would be silly. But just because I was willing to sink 2k$ into hardware doesn't mean I would ever have spent that much directly into BTC at the stage when I entered into mining so the 2 are never directly comparable unless we start talking about a larger scale of investment.