Of all the throws in the world, the open-side swing has to be the most brain-crippling, vision-destroying pass of all time.
I went to play mini with the Ego boys last night (first time playing ultimate in two years) and came away thinking what an awesome game mini is. Great for conditioning, great for reps on o and d and great for seeing space. The combination of the tiny little field, make-it-take-it and stall-from-anywhere means that the funny space abounds and is used frequently. In fact, if you never use the funny space, you probably won't score in mini.
For so many ultimate players, learning to throw an open-side swing was their first or second throwing skill. It was an essential skill before their team would even let them on the field. But in learning the open-side swing pass first, they immediately put on mental shackles. All that funny space, which is so easy to throw into and so easy to cut into, disappears because it's a break-mark throw (which is a "tough" throw, so how could a rookie make it?) or it's counter-flow (which is a "bad decision") or it's just unconventional and unexpected ("that's not what we do.") Learning to throw that open-side swing pass takes a 4800 square foot field and makes it 10x10 box.
When you learn what a force is and a swing is and what the 'right' way to play is, you are excising a whole host of options and possibilities from your game. The really great throwers and cutters spend years unlearning what is and isn't possible. My advice: don't throw swing passes in the first place.