Samuels, as to your statement:
"I am not exactly sure why this change was made, but I am sure the code making panel had a reason behind it"
My response is EXACTLY. When I was a design engineer we were required to attend NEC seminars, and some of the gentlemen who taught them were on the NEC panels and explained the process. The group that makes up the NEC is NOT just one man but a panel of the finest experts in the business and believe me when a change is made its ONLY AFTER numerous experts and evidence and study and thorough review have proven its absolutely necessary. Many changes have come about because someone was killed or a building was destroyed and there was a thorough investigation.
The reasons for single point Grounding and NOT mixing and matching and substituting Grounds for Neutrals and Vice Versa and NOT rebonding Neutral to ground at sub panels has to do with the fact the equipment GroundING Conductor is to carry ONLY fault current while the Neutral is intended ONLY for carrying normal return current. Once you start paralelling them they can carry each others current and the outer metal shells of appliances (given the right set of wrong circumstances such as shorts or opens or other faults etc.) which is designed for connection to the Ground Buss can be compromised......
See my answer to JD below for a bit more, but this is too much to cover here what can take books to fully comprehend, and Ive learned enough to trust the NEC experts over the untrained Billy Bobs of the world if it means my life may be at risk
As always yall are free to do as you please, dont take my word for anything, its your life at risk not mine.