some will not want to use imperfect model at all, but that is going too far, and would have prevented any progress in human knowledge

Key word here is "use."  

Developing a Model is an iterative process of taking a swing at it, testing, re-formulating, re-design, re-test, reformulating, until a valid (True + Accurate) representation of the phenomena is derived.  A big problem occurs when modelers develop intellectual psychosis, meaning they have derived a non-valid Model and then stopped testing and re-designing.  Neo-Classical Economics is one example, Freudian psychology is another.  

When this happens using the Model leads to inappropriate decisions and actions.  

She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre