How many times have you been in a situation where you have a charged attack and a pressing disincentive to use it? I'm willing to bet it's a non-zero number.
It seems strange to me that we can't effectively shield-cancel a charged attack to avoid using it at that present moment. In addition, I don't think this is too extravagant of a request (compared, perhaps, to others in this board) and would simultaneously be a) seamless for the vast majority of users, as well as b) help out some folks who could benefit from this change.
Thoughts?