My mother never ever ever washed a baking pan. Scraped and wiped down, sure. Water, never. She is still using the baking pans she got as wedding shower gifts nearly 45 years ago. They are all blackened and non-stick from years of seasoning (by use). Once when she was out of town, my dad took a grinder to her roasting pan to "clean" it up. She has never forgiven him for bringing it back to new condition.
I have been through numerous high-tech and low-tech baking pans. I'm not sure how much of it is washing and how much is different materials than what was in use back when my parents got married... nonetheless, I cannot convince my better half to stop washing them so I will never know.