Same here. I don't see why they can't do a two day event. I would guess there's the whole "cram in as many sponsors/potential sponsors as you can" desire to keep three days, but other than that there's no reason why a practise session or two on Saturday, qualifying and race on Sunday. Or one practise and qualifying on Saturday, race on Sunday, perhaps with a half hour "warm up" in the morning like they used to do.
I'd be happy to see the teams allowed to run a quali setup and a race setup. Allow them to use the half hour warm up to check the changes.