Of course they're hypothetical. But you were discussing the hypothesis. And if you're going to claim the lability of RNA prevents such an organism from existing, you have to address the objection that the organism had surely evolved a means to protect its RNA.
And while you are at it also complain to MIT.
At one stage you used to use primary data to argue your point. I'm disappointed you're resorting to duelling quotes. See, it doesn't matter if Jim Watson himself told you RNA double helices aren't stable, there are at least a half dozen perfectly stable RNA double helical structures in the protein data bank. Try this or this or this.
The point of this discussion, is that it is almost a consensus that RNA is too unstable a molecule to be the origin of life.
No doubt there is among your pals at Designed Universe.
The objection is that the organism had to exist before it evolved a means to protect its RNA.
And of your examples, the longest is 46(23) residues, not much of a life precursor.