I kept hearing that, so I went to Wal-Mart last fall and got a set of Magna-Grips for my Saturn, only to be dissapointed when they would spin just as bad as all-seasons on ice (I guess they're studdable for a reason, maybe I should have got some installed). Then the big dump of snow came in March and I was driving circles around everyone and I finally understood what the big deal was.
I think that statement is more to make a point than it is true. In any case, winter or summer, you want to buy good quality tires. And in may casses, a good quality winter tire can cost less than the summer tire for the same car - if you are able to on your vehicle and willing to do so, you can usually minus size onto cheap steel wheels, and often the whole winter wheel/tire assembly can cost less than just the summer tires alone.