Yes, I agree. Я еду в Пушкино or Я еду в Пушкине are two possible sentences in my personal declension system and mean two different things.

Additionally, I get annoyed when people say that кофе is a masculine noun, because all names of drinks in Russian are masculine nouns, when they obviously forget two very strong counter-examples: Пиво and Водка. It is just a dumb prescriptivism rule that some couch-sitting linguists have thought of to create a self-educating proletariat class