No, he really didn't - he said specifically, "So many, many things can be wrong and make a planet uninhabitable".
What if Proxima B has chlorine in its atmosphere? Uninhabitable.
Proxima B is a tidal-locked eyeball planet - what if the equatorial stable zone still shifts enough to not provide a stable environment for life? Uninhabitable.
What if Proxima B encounters too much ionizing radiation? Uninhabitable.
You've managed to ignore the sentence in the post that I did reply to. You know, the other one.
You've also apparently not payed much attention to Sure, we don't know a whole lot more about it, so it is quite likely to not be a nice destination for humans, but it seems to be at least remotely Earth like. that I said above (surely my making that statement implies some use of my imagination prior to your suggesting it).
I think we're all on the same page here. Just because something is in a fortuitous orbit, there are still a thousand things that can make it miserable or uninhabitable. Even earth, aeons ago, we would have found uninhabitable. Its very likely we have evolved for exactly the earth we have. To find another anything like it is astronomically unlikely.
