You missed the point.
The point being that the Europeans were once those African's. Those Europeans were once as vulnerable to the hash Ice Age climate of Europe, but they learned and adapted.
Same will be true of Mars.
After enough time, Naysayer are almost always wrong.
They once said flying was impossible.
They once said going to the Moon was impossible.
They did not have the knowledge, nor the vision to see what could be accomplished. They were wrong.