The Facetime light was already exploited and disabled. Google, "isight light hack." That has since been patched, but it reflects that even such security measures don't really amount to much. It's because of that almost ten year old exploit that I think it's probable that someone thought a way around the patch, and never published it.
I think most people are generally better served by a monitored and secured datacenter. Considering that most people have no idea how to secure their computer, or monitor it for intrusions.
Personally, I would rather trust my files in an encrypted datacenter that is almost physically impossible to penetrate, where paid white hat hackers proactively monitor it and patch it 24/7 ... than to think my unmonitored, encrypted laptop is more secure. Granted, a datacenter is a juicier and more obvious target, and my data might be a consequence of someone else's targeting ... but my laptop is significantly more hackable, albeit less targetable (unless I connect to public wifi).
Pros and cons / tradeoffs with each, so it's really a matter of perspective.
But personally, I'm very experienced in professional computer security, and even I don't have the patience to monitor my laptop. With Windows that was a daily task, with MacOS's true / pure Unix subsystem I'm less concerned. But even then my laptop is basically empty, and everything is on an encrypted and multi-firewalled NAS, with SELinux secured and encrypted off-site, ssh key only accessible, single point of entry backups. I'm certain my cloud backups are more secure than my NAS. I put significant effort into it because I knew it was in the cloud. That logic is similar in other cloud versus laptop situations, that because it's "the cloud" more effort is put into security.