This approach would be similar would be along the lines of the Samsung/LG/Sony HTIB that have tiny little 3ohm speakers and a little sub. The optical drive is built into the "receiver" and usually has little or no inputs. Once a part fails, the entire unit is garbage.
Building this into a TV would be about the same and the reason almost nobody does it is because they are in the business of building TVs, not total A/V systems. They separate them for good reason. The more you combine, the higher the chance of failure.
I know some of the super high end TVs have this, LG in particular, but what happens when a part of the sound bar fails? Or the connection between the bar and the TV? I would rather not toss something that expensive because of a failed cable/speaker.