I've found the opposite to be true, once you get into the knotty gritty there's so much that can be customized to different use cases. You can have different organisations and 4 levels of user roles. Lots of ways to handle authentication, a great API so everything is scriptable and lots more. It may not quite fit your needs but there's been a lot of effort put into the details. I'd been interested to know the specifics of what you couldn’t achieve with it?