Not a silly question at all, this is something I really should write about as to why I won't be making Portal 2, but the short answer is that a demake of a game of this magnitude would simply require too many manhours to do - there's so much going on in that game that it's mindboggling!
The final release for Aperture Reconstructed should be out shortly however, I've been busy putting all I can into the game and trying to nail every problem there is - the duration of this offers a valuable insight into just how much one person can realistically achieve also, sorry to disappoint!