[least]

That's certainly true, and it is a strong 'selling point,' so to speak, for open software. But openness is just one feature of many that people use for making considerations about the sort of software they run and frankly, for an average consumer, it probably weighs extremely low on their scale, because in either case it's effectively a black box, where having access to that information doesn't actually make them more informed, nor do they necessarily care to be informed.

Most people don't care to follow the controversies of tech unless it becomes a tremendously big issue, but even then, as we've seen here, there are plenty of people that simply don't have the technical acumen to really do any meaningful analysis of what's being presented to them and are depending on others to form their opinion, whether that be a friend/family member or some tech pundit writing an article on a major news organization's website.

Trusting Apple presents a risk to consumers but I'd argue that for many consumers, this has been a reasonable risk to take to date. This recent announcement is changing that risk factor significantly, though in the end it may still end up being a worthwhile one for a lot of people. Open Source isn't the be all end all solution to this, as great as that'd be.