The ineffective nature (or absence?) of good vetting to prevent these dodgy apps is lamentable. We know huge numbers of users are incapable of noticing, or unaware of, such potentially dangerous signs like incorrect grammar, so only way of prevention is to protect them from themselves, by systematic and thorough vetting of apps available.
Why would any one install a security app apart from a firewall, on a UNIX system - that's what Apple is based on. Same reason people don't install AV on Linux.
Maybe because macOS isn't really more secure than Windows? Even if it is, there are uses like preventing Windows machines from being infected by your files, shredding, VPN, etc. As for the article itself on the iOS App Store, all I'm surprised about is how many say Apple vet it more carefully than Google.
