> “X uses Y therefore Y is good” in general is a terrible argument Which is not his argument. His argument is "X uses Y, and X doesn't have problems with Y, so

> “X uses Y therefore Y is good” in general is a terrible argument Which is not his argument. His argument is "X uses Y, and X doesn't have problems with Y, so Y is good enough for X at least". Which is a completely valid thing to say.