Default [Q] Hotfixes on Antivirus Apps--how accurate?

Couple questions here.

360 Mobile Security gets plenty press by claiming it provides hotfixes. I haven't noticed new ones since 2012. I've noticed the same hotfixes offered to users upon installation of the app put onto any android I've observed to date. Obviously we're well into KitKat now, so are these hotfixes redundant by now due to upgraded systems since then? If not, then why haven't these issues been resolved with carrier or custom firmware by now? still claim to be exploits that your android needs even on the most recent phones. They explain what kind of exploits they'e patching, but not referencing the specific alleged exploit.

For older phones not yet rooted, does CM Security and/or 360 Security fix the MasterKey exploit and other older ones now fixed by JB 4.3 and KitKat? They don't mention that they do, yet they may do so. They also do not discuss whether they address dirty USDD issues, etc.

Thanks for any responses.