Much like it's hard to give much credit to sentences that use common nouns at all; we would be better off without them, they only lead to generalizations.

In fact, I should take it all back, for I find in the process of communicating like a normal human I've generalized the very notion of improper nouns. Not all improper nouns are the same. And I've generalized generalizations themselves; not all of them are bad. Mea culpa.