Nobody shops on the App Store because it's more secure. They shop on the App Store because that's the only place to get apps on the phone.
That's like saying that users just love being routed into a Linux distro's central repository after already finding some software's website and a download link because the repository's safer, and not just because the Linux installation story is a user-hostile pain in the ass that saddles everyone with an artificially limited and out-dated set of packages unless you happen have the time and know-how to compile everything from source.
Or it's like saying that Windows users love viruses and malware and that's why they keep downloading Paint Shop Pro 9 Cracked!!~!! from DipshitForum.com and its ilk and then wonder why their computer is so slow and "needs replacing" every year.