Yeah, I agree that redundancy is a problem. The idea that the reader is stupid is the cause of quite a few mistakes, in my view. Anything from redundancy in dialogue or exposition, to infodumps because the writer is sure the reader won't 'get' what is going on unless they pile on information. It also leads to clumsy, heavy-handed delivery of themes, where instead of letting the work speak for itself as they should, the writer is convinced the reader don't understand what they're actually saying unless they hit them upside the head with it.