Aiming directly at the contact point will result in an under-cut on most shots, unless I'm missing something in the original post. Yet, many in this thread said they aim this way. Weird.
without getting into another debate about collision induced throw, i do agree with your statement... but i think over time, at least for me, i've started to learn which angles result in under-cutting so i'm automatically changing the contact point. although, for really long very thin cuts are still near impossible for me, and i know it's because of how i aim... with my system, i'd have to aim on a spot next to the ball, not on it. i'm still learning those.