I think we stray into a more objective realm when discussing the intentional silly that makes it into these games. Getting a ride from a crazy cloud giant wizard flying in a tower that looks like a silly wizard hat (who wears those?) who seems to exist only to the the adventurers into the plotline from the hastily tacked on rush to 5th level that is Chapter 1 is verging on objectively silly and bad. Well, it is objectively silly, bad is more subjective as many seem to like silly. It does clunk hard, though.
Yes, though thankfully the writers have not yet stooped to the lows seen in Castle Greyhawk.
Many of the OP points were more to the types of omissions that occur from single author creation with limited proof-reading and no dedicated editor review stage that happens because of time/cost constraints. Objectively silly bits often get pressed into the works for their own sakes -- the silliness is treated as a selling feature. It works sometimes; more occasionally for some groups than others.