To further elaborate:
Besides being inconsistent, your criteria are arbitrary.
And they are your criteria. You've got a serious problem with ownership of this article; it's very nice that you've done so much work on it, but if you want to enforce your own version on everyone else, Wikipedia is not the place to be publishing.
How ironic that you're complaining about me removing "relevant cited information" (ie. one guy's opinion) from the introduction while you are at the same time removing relevant cited information from the body. Scholars describe it as a genre. That is enough.
You claim that adding this genre makes the list useless to the reader, but that's a very silly claim, because quite the opposite is true: suppressing genres because of the opinion of one writer (or really, because of the opinion of one editor) makes Wikipedia a less useful and trustworthy reference. In Rescue opera, we can go into detail about scholars' thoughts on its coherency as a genre, but the list structure of this article is not set up to deal with competing theories: Charlton's opinion that everyone else is wrong has no place here, and certainly not pride of place.
"As already explained..." - that's rich. You pretend that there was some kind of consensus which I'm violating, when the talk archive you link consists of you, you, and more you; indeed, when Talk:Rescue opera contains more users supports its description as a genre.
– (talk ⋅ contribs)