Unwilling? No, HN is more than willing to have a good debate. The issue is that with some particular topics, HN is unable.
HN is not a perfect platform for intelligent discussion. It is unable to handle certain types discussions and the only effective mechanism it has to keep those discussions from consuming the rest of the site is to crudely cull them.
Humbly, I suggest that if HN's inability to discuss some things surprises you, then your opinion of HN is too high. It is imperfect, very imperfect.