Your first point is empirically false, though I'm too lazy to look for links. The second point seems circular, but doesn't matter in any case, since the idea here is to have good conversation with each other.
And as people who refuse to see other viewpoints go—would you say the same about posts from people who believe that, say, mass surveillance is bad, or net neutrality is good, or Apple should not cooperate with subpoenas for user data? The authors of those posts are also very unlikely to see opposing positions.
Proof?
> Moreover, this particular point of view is from a radical organization
Define "radical."
> you can't really have intellectual discourse with people who refuse to see any other position than theirs.
How does one tell if this is the case? How does one tell _which_ party refuses to see things from another position? How does one tell if it is in fact miscommunication, or lack of a shared understanding? How does one tell if in fact one of the parties is not discussing in good faith?