Agreed that the upload queue solves this problem, but, one thing about the current system is it lets people choose where on the continuum they want to be depending on their risk/reward profile.
I would suggest the current system fails to efficiently choose (as you have to align multiple pathways, like updates, "manual" installs, adding new packages), and so effectively there's only the illusion of choice. Switching instead to a queue not only means that there's time for QA/security scans, but it's much easier to make the choice to speed up than slow down.
FTA, "even make the queued releases available for intentional, explicitly volunteering beta testers to try out." Under the proposed system, you have to opt in to the insecure early releases. Rather than opting out of them. Which seems like a more secure default!