In my own experiments, I discovered most of the dust actually escapes between the table bottom of the table and the top front of the lower saw guard. A few of of us have rigged various dust "deflectors" that partially sealed that gap, and the other lesser gaps. There's a lot of moving parts to this, literally, between making sure you can still tilt the table to cut bevels and open up/close down the lower guard to accommodate wide dados or moulder heads and table tilt. There isn't an easy engineering solution that maintains all the functionality of the table saw, which is why I suspect Shopsmith hasn't offered an improvement (although if they would offer an upper saw guard with a dust chute a la the Sharkguard, that would help!).
Gale's Law: The bigger the woodworking project, the less the mistakes show in any photo taken far enough away to show the entire project!