[acituan]

You missed Heidegger being an outright Nazi, and not even a rank-and-file one.

Not being able to relate to an other if they are not pure is a failure in having strong enough ego boundaries. High functioning requires complexification of our boundaries; a confidence in deciding what goes in and what doesn't on the fly without requiring rigid codification of rules, which ultimately requires a confidence in ourselves; what we are and what we are not.

All-or-nothing purity is a way of keeping things simple and reducing the complex calculus the reality demands. Not saying this in a demeaning manner, because we all do this in varying degrees. But if one can't tell if they are being a "bad" person or not for making use of a "bad" person's valid idea/product, that could as well be a shortcoming of their own self-conceptualization than the "badness" of the other.