Right. If you have some kind of frame sag or damage, that should be addressed prior to any alignment attempt.
But the offset bushings allow for a far greater caster/camber change than what is necessary for just the radial changeover. Most people like the road feel additional caster gives. It's great for good steering "returnability" coming out of a turn and that same force is also what keeps the car going straight down the riad.
With positive caster, you are not just turning the wheels. You are also lifting the front of the car up as well. This is where the returnability and road stability comes from. The force of gravity returning the car back down and the wheel straight at the same time.
All that said, you can get to the point of too much caster, where it feels like the car is going to "fall over" when you take a turn. It's a really strange sensation.
