Misunderstanding Heidegger I agree. However and so as not to be misquoted or taken out of context, the words you selected to put in quotation marks do not represent my views. Instead, they represent my interpretation of Heidegger's views with which I do not necessarily agree.
Though I am not convinced that all philosophy is quite as local as you suggest. In fact, I am quite confident that most of the early Greek philosophers considered themselves to be expounding more on being in general rather than Greek being in particular. Though you could be absolutely correct and they could all have been fooling themselves.
After all, human being is the being that questions being and that is true cross-culturally.
It is only the answers that vary between cultures.
And the answers are far less interesting than the questions.