Our TVs stretch 4:3 content so let the end user watching the program decide. This way those that like distorted images can continue to stretch 4:3 content in various ways and those of us that like the best picture possible can leave it in the aspect ratio of the content creator.
I wish people would lay off of this argument. As has been stated time and again by a number of users of this forum, there are a good portion of people with TVs that don't stretch content that is prepopulated with pillar bars. However there are also many of us who have tvs that *will* unstretch content.
So instead of saying it should be done how you want it to because that works fo everyone, you should realize that it DOESNT work for everyone.