Is it bad that they're constantly updating?
When it goes against user experience, then yes. Progress can happen by adapting or changing something gradually over time, not by killing a module completely. Think of those people who are already using FBML pages, what will happen to those pages in 1 or 3 years time? Will they still be supported? Facebook has evolved beyond anything imaginable, and as such it has to take care about changes. It's changes affect more people than any government could affect, and as such it has to do things carefully.