Why didn't Pam want to move to Philadelphia?

I'm about 3/4 of the way through S9 so not sure how things end, but why is Pam averse to moving to Philadelphia? In one episode she tells Jim she 'liked their life' in Scranton but I don't recall her elaborating.

Jim's new business seems successful and you'd think Pam wouldn't mind the chance to do something new after all the years at DM. Plus, she'd likely have more opportunities in the art world, or other office jobs in a bigger city like Philadelphia vs. Scranton.

Why do you think Pam was so set in staying in Scranton?