From all the interviews I've read Sarah treats the show like a Job, not a summer camp. Her friends and social life seem to be restricted mainly to people outside the industry, especially her best friend (was she named Nicole? - something like that).
I actually admire that. She isn't there to make friends, she is there to make a living. It shows she has grass roots - she is loyal to the friends she always had and doesn't feel the need to surround herself with glamour. I think she's made very wise choices there - I find that people who structure their social life around their jobs usually are disappointed in the long run. With ScoobyDoo2, a relatively recent husband, and friends and family not on the show, Sarah would have to be very discerning on how she uses her time. I see nothing wrong with that; nothing deserving of shame.
It's natural that we as fans of the show want her to value the show as much as we do, but when it comes down to it, she hasn't experienced the show the way we have; as a fictional story with mysteries and ups and down. To her, it is a job. As a comparison, I never went to the christmas party of one past job I'd held for 5 years, simply because I knew I was going to leave. I liked the people there, but I didn't feel any need to pretend that they were the people who mattered most to me, because, quite simply, they weren't.
In that sense, I don't think we have any right to dictate how SMG should act. She has a busy life, and is as driven as a woman her age can possibly get. We don't see her agenda's, so it would be very bad taste to suggest that we know what she should and shouldn't do. We have to accept that while we may love the show deeply, she probably doesn't. She never got to watch the show the way we did. To her, it would just be a job. How can we blame her?