Joseph: There is no need to be apologetic about not knowing a language. That is logically absurd.
However, when one is talking/writing/posting to an audience that speaks a specific language, and they cannot communicate effectively, and they are belligerently defensive and even proud of their ineptitude, then there is nothing to call them other than idiotic. And nothing short of disclaiming their proficiency in that language before their piece is going to make them look less like a blundering fool. Again, there is nothing wrong with not knowing something. But putting yourself in front of those who do and and proudly claiming ignorance is a good way to prove yourself impervious to knowledge of any kind.