A small comment if I may...
It seems that the fundamental difference between Zope and all the other web frameworks I know of is simply that all the others are not frameworks.
A framework expects you to embed and extend inside the framework, its metaphors and its design decisions. A library expects you to access it externally, and if you do not like its design decisions, it does not matter that much because you are insulated from the library by a fairly well defined interface.
For a Windows analogy, most Pythonistas seem to prefer libraries, probably for the same reason Word is seen as a COM "server" more often than a COM "client" - its a lot neater to control Word from python and shove any data it needs in than it is to use Word as control point and create Python objects to serve it.
And so we tend to avoid frameworks in a similar way most of us avoid developing for Word.