Remembering when I was small, where i played countless hours with lego. Built many interesting constructions and tested the strength of many designs. That was a form of modeling the behaviour of a bridge, house or any structural analysis that I could think of at that time. We all model things every day since we need to live in this world and figure out even if very basically the behaviour of objects. Think that when you hold an object you use the right force to hold it. Some how we know exactly the necessary configuration to execute physical task even without any though what so ever. When we look at a design and it challenges our notation that it will work it is because our underlaying protective system already is calculating and giving us feedback that it is dangerous to use. However this feeling can be wrong and the structure can be very safe, however most of the time our body is wright :).
I tested two designs on the simple table to understand what would happen.
This design present complete load transfer to the legs. The connection between table and leg is compress. Very little to none torsion is present. This design looks very stable, simple and is the classic, maybe the only simpler alternative is to use a solid cylinder instead, but that would make the seat very heavy. This design probably will hold as much as what the material used (wood, iron) can handle.
Comparing one design with another we can see that the behaviour to pressure is completely different. The straight legs approach is stronger and would deal better with increased weight on top.