I use Facebook pretty much exclusively as a way to discover and congratulate people on major life events (birthdays, weddings, babies, etc.). I use it maybe once a week, but I actually really do appreciate being notified about e.g. someone's birthday - it's a gentle reminder to catch up with that person.
The first time I got one of those generic "Jane commented on her status" notifications, I assumed something major had happened: Someone had passed away, had a major life change, etc. Of course, it wasn't that - it was something much more trivial.
The birthday notifications/etc. are useful enough that I keep the app on my phone, but the incredibly vague "so-and-so updated their status" notifications are pushing me towards finding alternatives.