Why Moles (shims) frameworks are very less [on hold]

With consideration of difference between Mocks and Moles, as they say: "The MS fakes framework supplies stubs and moles (shims), whereas NMock, RhinoMocks, and Moq all provide stubs and mocks......MS fakes framework uses generated code, much like Accessors in prior versions of Visual Studio instead of generic types.....With NMock, RhinoMocks and Moq, you generate a mock object and then use that object to specify stubbed return values or to track interactions":

I think there should be more such Moles framework. I searched for more Moles framework but just got two Moles (Shims) Framework : one introduced by Microsoft and Typemock (I am already aware about many Mocks frameworks).

What are the reasons as so many Mock frameworks exist but not that many Moles (Shims) frameworks? Please share name and your experiences with other Moles (Shims) Framework too. Thanks in advance.

P.S. It is not specific to any language or platform. I would like to hear about any Moles (Shims) framework out there. Thanks.