It's not a contradiction. Removing that setting solves that problem, but it's not the only solution.
And, you don't need an app, I would imagine most scamming is done without an app.
So, really, we're solving a subset of a subset of a subset of a subset of the problem.
The most effective means of hacking is social engineering. You can't solve that with any number of "security measures". If you require all the DNA sources in the world, a scammer will still charm a target into opening it up for them.