"could a grounding potentially make a evacuation situation worse with a large passenger vessel"?

The short answer is "yes" but if the ship was already listing at an extreme angle she might have capsized in deep water. The question is whether it might have been better to have deployed the lifeboats while the list wasn't quite as extreme in deeper water. While in deep water Capt. Schettino decided that it was better to ground the ship on the point, and swung the ship around 180 degrees to do so.

Charley Noble