IMHO, the beauty of some frameworks is the use-at-will architecture. The advantage here is that you can exchange components for a better implementation — or let’s be honest, one that’s more appropriate situation.
I’ve seen a lot of frameworks and my biggest issue with custom frameworks is that no one but either one developer or a relatively small team see the code. And in this situation anyone is more likely to screw up sooner or later than in an open environment.
When people complain about frameworks, they often forget that frameworks are not written just for them or for their particular use case. No, a framework is written for a wider audience.
The better frameworks communicate this fact very well and allow developers to replace components, or plugin their own.