Unopen in a sentence as an adjective

It's really quite depressing to visit Hacker News and see it filled with people being unopen to intelligent ideas to make things better.

Which is somewhat of a shame, as it makes the posts very one-sided and unopen to debate, which is what appears to be happening here in the HN comments.

Unopen definitions

adjective

not open; "the door slammed shut"

See also: shut closed