I have the same experience with front-end wizardry. By the time we were sketching & discussing it, that guy just created a real thing. Much faster than any Axure.
I understand it is not easy to build that level of skills and craftmanship, but it is not impossible.
I am thinking of building UI Inventory, not customizing Bootstrap or any other existing library. In the inventory, I would only have elements I designed, elements I need and use. I use only two styles of buttons and one list. On the other hand, I need a couple of custom components.
So I don't need anyone to maintain a full bootstrap library with file loading dialogs or calendars. There is no calendar in my app. I want always up-to-date subset, that is much smaller than these generic libraries and framework.