Even though most micro donks are only thinking about their own hands, isn't it true that there might be quite a bit of value to taking down a big pot at showdown with 65s, esp. if it cracks AA or something equally impressive preflop?

The whole fishy table will think "that guy is a donk" and play you accordingly. In my experience, while they ignore pots that don't go to showdown many microplayers do pay attention to people's hole cards on big pots, and then overgeneralize.