There are two problems with knots. The first is that as the knot tightens, it tends to cut itself in half. A bowline is a prime example - the small loop section of the knot slices through itself.

The other issue with knots is the loading of the braid. The outer part of the curve will take up most of the load, while the inner part of the radius will be "relaxed". This results in a greatly reduced breaking strength because you are really only using 1/2 the line to take up the load.

I really need to get a video camera, film it on the punisher, and place it on you-tube...