History of (Western) philosophy

The article on the history of philosophy follows a grouping of cultures that ties together similar waves of thought. These cultures include Eastern, Western, Abrahamic and African philosophy. But even with all these different schools of thought, the one the article had focused the most upon was that of the Western philosophy. I understand that much of the teaching of introductory philosophy will concentrate on western philosophers like Socrates and his student Plato. But why is it that we concentrate so much to this culture?

"The Indian or Hindu schools of philosophy can be considered the oldest schools of philosophy" but then why are we not learning about these cultures if they are the history of philosophy, the beginnings? It is important to learn several types of philosophy to be able to discuss the different schools of thought efficiently and in a manner that would evoke good discussion. For example, in debate one must be prepared to argue both side and know the points of both sides to properly discuss an issue, I believe the same should be done in philosophy and taught to philosophy students.