When Gatekeeper was originally introduced, along with the Developer ID program, its goal was to prevent the widespread-- prevent the outbreak, a widespread outbreak of malicious software. But over the years, its goals have broadened a bit.
And now, it's designed to protect users from running malicious software while leaving them in control of what they run on their Mac.
...
Our goal is to make every Mac user safe by default, but not to prevent you from running the software that you want to run on your Mac.
And that means that there will always be a way to run a specific piece of software that you want to run on your system. Now, I talked a little bit earlier about how every year we're continuously improving the technologies and policies that we have at every layer.