>Then maybe we should start using languages that have no type-safety whatsoever, perhaps?
Only if we kill all of the stupid people.
>We have to sacrifice something for a better goal.
So we'd be sacrificing C++ code quality for decreased C code quality? Normally a sacrifice results in improvement elsewhere, not deterioration. This sounds like a lose-lose scenario to me.
>A lot of C code can be converted into C++ code with little effort.
Idealistic ignorance is unbecoming. There likely isn't a C code base in existence that can be converted to C++ without a lot of effort and resources.
 That wasn't specifically written with C++ compatibility in mind.