It is actually blocked. The program is prevented from launching. You can go into the security settings and approve it and then relaunch it (which last I saw, the error message didn't even tell you how to do anymore), but it's not just a "approve/deny?" skippable screen.
By that same logic, non-hsts SSL certificate expiration warnings are browsers "blocking" you from visiting a website, despite the buttons that allow you to bypass it.
In Chrome, it's even more complicated. You have to click the very small "More/Advanced Settings" text which doesn't even really look like a button. After that, a button allowing you to proceed appears, but upon clicking you are given a very scary warning.
It's not the same. In the SSL case the browser gives you a bypass button, which is fine (if hidden). Here, there is no bypass button unless you have the secret knowledge to open the app in a certain way.
Otherwise the OS entirely refuses to open the app with no bypass button or hint as to how to get around it, while implying "security issues" and "untrustworthiness"
For certain cert errors in Chrome, there is no button/link to ignore and continue. You actually have to type "thisisunsafe" into the tab. There is no feedback when you are typing this. It will just navigate to the page you were trying to reach as soon as you finish typing.
