Re: Top navigation bar, main bar, lower bar, double menus why so complicated?
The idea with the included bphome/bpmember themes is to be a skeleton framework to build off of. It shows how to use all of the included functions and loops in a way that makes the output of each element clear and concise.
It might not be the cleanest theme available, but it’s a great start if you’re learning BP or you need to understand what files do what for what reasons.
In my opinion, an experienced BP developer should be able to create a unique template starting from the bphome/bpmember themes and working outwards, within a few days. There’s no doubt that BP themes are extremely involved, but that’s likely to change as the platform matures and WordPress better supports theme locations and child themes.
Long story short, you’re probably right, but don’t expect the included theme to get much fancier. (Look at WordPress and bbPress for example. Both included original themes are very primitive in their designs.)