The concept is that "He said" and "She said" blend into the background, whereas strong-verb attributes direct attention to the attributes and distract from the conversation.

There is more than the adverb wrong here. First, the question mark tells the reader that a question is being asked. Stating it a second time with the dialogue tag of “asked” is a classic example of a redundancy see far too often prose. The dialogue tag of “said” does its job then disappears in the reader’s mind—like a well-mannered tag should.

Regarding the adverb of “innocently,” I read recently, that Stephen King said adverbs were made for lazy writers. Vonnegut would likely agree as only one adverb, the word “sweetly” appeared in all of Slaughter House Five. Even then, I believe it was used sarcastically.  In short, the best argument  I have heard against adverbs is that they tell and don’t show. They cheat the reader out of an opportunity to see through action and description.