I don’t think that statements like “betting your life savings on Bitcoin is a bad idea” is any kind of legitimate criticism of the currency since no one in their right mind would suggest that. It is inherently risky, as pretty much anyone will tell you. However along with that risk comes the opportunity to make a lot of money by actually saving, which will get you nowhere with most world currencies that are afflicted by inflation and low or non-existant interest rates.
I read this article this morning, which I recommend: What Bitcoin is Teaching Us. It offers a fair comparison between our traditional idea of currency (including elements of central control like inflation and FDIC insurance) and how Bitcoin is different and better. A crucial distinction is that Bitcoin cannot be seized by corrupt governments. Not only did Cyprus believe that their money was protected, but even the US has a terrible history of defending the savings of its people, not only because of the Greenspan era of economics which destroyed the idea of saving and created a consumerist economy, but that even investments considered safe like gold haven’t always been that way in the 20th century United States.
Edit: I also saw this video on Vimeo which is the best explanation of Bitcoin that I’ve seen so far: