It means that it cannot be endured, that it cannot be tolerated, that it cannot be accepted. Which is difficult to deal with or arrange. Impossible to accept or abide by. Unacceptable, of poor quality, with no possible use.
"Unsmokable". Argentinism, lunfardo. 1 . Referred to "person" or "thing", difficult to accept, unbearable. 2 . Annoying, annoying person.