I find it interesting that most pure constructivists get attached to instructional methods or one particular method, usually some form of discovery learning. I've worked in an environment with instructional designers from the constructivist camp. I learned a lot by watching how they designed and evaluated instructional projects. Some of their methods are commendable but a large part it is not well suited for all learning contexts or outcomes. Try working in a corporate environment as an instructional designer with a mandate from upper management to produce results in the form of new skills and behaviors within a given period of time and a limited budget.
Flexibility is the key.
The more options I have to employ in terms of selecting instructional methods the more influence I can have on learners. Constructivists in a way are doing a disservice to the field of instructional design by telling us that we shouldn't use certain methods because they are not philosophically sound. The point is that we instructional designers need to get real. A variety of instructional methods can work depending on the context, desired outcomes and learners. Please forgive me for lecturing to you.