Audio system packages tend to be of little interest to most people. When have you ever seen one advertised and thought to yourself, "now that's exactly what I would have done"? For me, the answer is never. And just because a system has synergy to your ears in your room is no guarantee it will be magic in another environment.
At least when you build your system over time you know when you introduce a new component if it's a good fit. It might take a lot of trial and error to get it right, but that's half the fun.