Transparency sucks. It's just a toy. It looks cool, but doesn't do anything, and sometimes makes things hard to see. "Sometimes" is often enough to make the whole thing a net negative.
If it looked cool and never got in the way, then I'm all for it. I'm not one of these anti-aesthetics weirdos we have roaming Slashdot. However, it does get in the way, so it shouldn't be used.
Lo! Men have become the tool of their tools. -- Henry David Thoreau