The USG also claims it's wrong for people to shoot each other all while maintaining an army of hundreds of thousands of people empowered to do exactly that, and worse, in the right situations.
But either way, "we" also didn't put anything in our "contract" that let them make nuclear weapons, air forces, computer inter-networks, or social security/welfare programs.
You're missing the word "presently."
That back door is there. Others not having figured out how to interact with it yet is a matter of security through obscurity[0], and the system is still weaker for it, even though it's not yet fully cracked.
[0] https://en.wikipedia.org/wiki/Security_through_obscurity