I hate to think of how many track and balance sorties I've flown in my time; it's certainly hundreds.
It seems perfectly obvious to me that if the lengthwise balance points / C's. of G. of individual blades are not the same, as well as their overall masses, once they are spun on a rotor head there will be imbalanced forces and vibration.
Some obviously haven't quite grasped the complexities. But I don't see it as a reason for insults to be "whirled around". It's a shame that some seem so keen to grasp their chance to belittle others because it spoils what could be a meaningful discussion.