You know what, as far as Pakistanis go, we are happy with our JF-17s. Be that if they're based off MiG-21s, doesn't matter one bit. What matters is that we have worked hard with our Chinese friends in achieving something which very, very few countries can possibly achieve. And that is to design, develop, manufacture and own source codes to make changes to the aircraft. That sort of freedom is priceless and it's that sort of freedom which cannot be leveraged under sanctions. So if anyone says that Thunders are based on MiGs, I say thank you and ask whom does your country buy fighter jets from?
Thunder gave Pakistan the ability to shape it's own future, without being blackmailed by another country on what Pakistan can and cannot do. And hey, it's worked out so well for us so far. As matter of fact, one can say that Pakistan has its cake and ate it! Got sanctioned coz of nuke program, developed Thunder program with friend and ally, China. In the end, not only did Pakistan become the only Muslim country to have nukes, but also an independent fighter program (free from West sanctions) but also upgraded and expanded F-16 fleet. So yeah ... MiG-21s, MiG-17s or the Bi-Plane. It doesn't matter to us Pakistanis, we are proud of working with our Chinese friends and achieving the impossible.