I have a big-screen projection TV at home -- we set it up this way to avoid burning in the screen at different rates for normal TV vs. widescreen. You'd be amazed at how quickly your brain adjusts for it... it only took an hour or two and now everything looks "normal" at that setting.
You are right. It just bugs me.
I am a bit more picky since I have done a little video production. We watch the analog/SD stations at the correct aspect ratio. No one seems to mind that there are black bands on either side. And we have a DLP monitor so we don't have to worry about burn in.