You suppose that there are no highly-paid researchers on the planet working on AGI? Because there are, and that's less proven than "porting one codebase to another language" is. What about Quantum Computers, what about power-producing nuclear fusion? Both less proven than porting code. What about all other blue-sky research labs?
Why would you continue supposing such a thing when both the employee, and the employer, have said that your suppositions are wrong?