Those who drink from double walled wine glasses shouldn't throw stones ... but really, as a general rule, no one should be throwing stones.
The first thing you're probably going to notice about these glasses is that they have two layers of glass. That's good for a variety of reasons. One, because it'll keep your wine the temperature you want to keep it while you're enjoying it. And two, because if you get surprised about something and accidentally squeeze it so hard that you break the outer wall, your wine will still be safe and sound.
In my opinion, however, the most important feature is the absence of a stem. Finally, someone got it right. I mean, keeping a stemmed glass upright is tricky enough for me when I haven't had a glass or two. And besides, I don't ever drink wine that's fancy enough to justify putting it on a pedestal. JMHO.