Well, you say that, but NTSC really is far from being the only way people are going to be using it. It's not even an international standard after all :-)
But this doesn't just apply to NTSC. All TV display formats are designed to utilize some amount of overscan -- NTSC, PAL, as well as ALL of the ATSC HD formats.
And particularly now - are most people really using theater view with TV out connections? Surely it's increasingly likely that people are going to be using something like a VGA or DVI connection from their PC given the number of TVs that have them these days...
It has nothing to do with the connection format -- it's an inherent design consideration for displaying images on TV's as opposed to computer monitors. It doesn't matter if people use VGA, DVI, HDMI, S-Video, Composite, Component, etc. ALL of these are designed to utilize overscan and have the edges of the image cut off by a small amount -- it's part of the design. The ONLY display format that is NOT designed to use overscan is a computer monitor, which is not a "Theater" device. It makes no sense to create a function specifically targeted at "Theaters" (i.e. TV monitors as opposed to computer monitors) and NOT take overscan into account.
I think that there are probably a lot more people using Theater View on TV monitors of some sort, so this would most likely help the majority of Theater View users.
Keep in mind also that if the Theater View display took overscan into account, EVERYBODY would still be able to use it. The people who want to use Theater View on a computer monitor would simply have a little extra space around the edges of the screen, which is far less of a problem compared to the way it is now, where it is simply not useable on a properly calibrated system due to the fact that important information is cut off.
To NOT take overscan into account, on the other hand, means that anybody who wants to use Theater View with a TV monitor will have to MIScalibrate the graphics card output.
I think