I was wondering the same thing! it happened to my mbmj faridah on the edges of the bag opening, but im not that bothered because the rest of it looks pristine even with heavy use.
i know this happens with long term/heavy usage and i think i've seen a thread where someone took acrylic paint and painted over the cracks.
i had a tiny tiny crack near the edge of one of my bags where it wasn't noticeable and i didn't have paint so i used () black nail polish!! it looks fine and i can barely tell now though
my hillier hasn't cracked, i've had mine for 7 months, but i think its around a year old since i didn't get mine NWTs and it was a older color (wine)
but my BFs gucci wallet has cracked pretty badly, i might get some acrylic paint and see if it works