Obviously not the OP, but figured I'll give my unsolicited opinion anyway.
I think there's "merit" to it, in that the logic holds: if we restrict the apps in an app store to be selected by a trusted entity then we can more likely trust the app. This computes, I think it's reasonable enough logic, but we could extend this further to something farcical too: I could make my phone "unhackable" and "more secure" by throwing it into a wood chipper. It would be impossible to hack, there's virtually no chance of my personal details leaking because of it, but of course I lose access to features of the phone (or in this case the entire phone itself). A corporation (or any large entity) will always be able to justify a restriction as a means of "increased security". Security vulnerabilities will almost always come from being able to actually use a computer as a computer.
This wouldn't inherently be a problem if it weren't for the fact that there are plenty of things things that are perfectly legal, but Apple won't approve, presumably out of fears of legal headaches, like video game console emulators.
My "solution" to approximate something decent would be to do something more or less akin to what macOS does. By default, don't allow any sideloading and only allow things to be installed via the App Store. If one would like to install something outside of the app store, they must (on a per-app basis) go into the security settings and allow things. This would still give preferential treatment to the App Store, but would allow people who know what they're doing to go around this.
NOTE:
I'm aware of the self-signing AltStore thing, and it's definitely a step in the right direction, if still a bigger pain in the ass than it should be.