I don't quite see how you've reached that conclusion. What I see myself (and I may be wrong) is that some of us think he has shown enough in those few matches to make the experiment plausible. Whether Rooney can actually turn into a regular (and excellent) CM for us is a whole different kettle of fish. That depends on how well he can adapt – and that is anyone's guess.
I feel, however, that many simply dismiss the idea because he isn't an excellent CM now, here and now, as we speak. And that, to me, isn't a valid argument. If Fergie actually plans on transforming him it will obviously take some time. Right now I too would pick Cleverley over Rooney as Carrick's partner in a midfield two – simply because Rooney is far too unproven. But I think it's worth a try – he may have what it takes. I think he does. It's not sheer desperation, as some have suggested – it isn't only because I suspect we won't buy a top CM this summer either. It's because he does look like a real prospect in the position.
But he needs to prove himself – if he doesn't adapt to the new beat, if he can't get the hang of the movement and the positioning to a sufficient extent – then, well, feck it. Don't play him there – but it's not like Fergie doesn't know that he's a more than capable striker as it is. I get the feeling some people think Rooney will be horribly wasted as a mediocre CM – but that won't ever happen. Fergie wasn't born yesterday. In fact he was born so long before yesterday it's practically a joke.