but were rejected on the grounds that they were Chinese or Indian?

I am quite sure that it is NOT the case that "philosophers are rejecting arguments on the basis of where they were first thought up." In fact, I do not think the problem is to do with Eastern philosophy being routinely rejected at all (for whatever reason, even considerations of validity.) Rather, the problem is that such texts are largely not even considered in the first place. Not only do academic institutions often make only the most minimal effort to engage with the Eastern canon, worse yet, they are rarely properly endowed, especially in terms of faculty, to adequately do so.

The Western tradition is not predominant simply because it is the consensus that it is superior in validity or soundness, but rather because it is superior in familiarity, at least for the people in charge of deciding what is available to study. If the education of your staff is not philosophically diverse, than neither will the education of their students be.

Now, that is why I think there is such an absence of diversity. Whether I think there should be more diversity is an entirely separate discussion. I see where you're coming from when you say that what we consider valuable for a study of the History of Philosophy should be separate from Philosophy itself. However, how should that distinction be made? Yes, one should evaluate the substance of each argument put forth, as opposed to who put it forth, where, or its significance. But how exactly does one do that objectively, seeing as philosophy is so void of consensus? Basically, I'm wondering what qualifies something for inclusion into a study of philosophy proper?

Is it necessary that it "match the philosophical community's standards of reasoning"? Ah, but that's the very root of the problem we're discussing, isn't it? Those standards of reasoning are themselves Western (insofar as they are derived from a Western tradition), and the philosophical community to whom Eastern philosophers must appeal (or "match") are thoroughly Western in orientation. Surely, to consider Eastern texts valuable to the study of philosophy only to the extent that they follow the Western tradition is somewhat unfair.

Many would make the argument, myself included, that what we generally refer to as "Eastern" philosophy is valuable not only to the history of philosophy, but philosophy itself, certainly to at least an equal extent as "Western" philosophy. I don't see why the value of Eastern philosophy differs so markedly whether we're considering history of philosophy or philosophy itself?

Nobody specializes in French Physics - because that would be dumb.

Yes, but everyone is familiar with the contributions of French physicists, because their achievments are invariably taught and highly valued. Conversely, while Chinese Philosophy need not be a specialty itself, the contributions of Chinese philosophers should be incorporated into other philosophical fields.

It isn't necessarily important that Chinese Philosopy be given its own field. As you mentioned, a racial or geographic qualification for a discipline like philosophy is just silly. What is important, in the end, is that works of Chinese philosophy are incorporated into various fields fairly, where they have something important to say (and they very often do.) The form that that incorporation takes is pretty irrelevant.

We think a name change is in order, as any university which purports to give an education in philosophy, but only gives one in Western philosophy, is lying to its students. Its saying one thing than providing another. Even worse than dishonesty, however, that institution is also frankly providing its students with an incomplete education. People who seek to be educated in philosophy ought to, in fact, must, be educated in philosophy, not just western philosophy. It would be like offering a major in Anthropology but providing courses almost exclusively about Africa, or about psychology and only discussing a specific field therein. So, for both the purpose of clarity and fairness, they should be more specific with the content of each discipline.

Similarily, we don't lament the absence of specialists in Chinese philosophy simply for its own sake, but because that often suggests that the academic institution is missing a very substantial amount of distinct and crucial ideas, arguments, etc. which all definitely deserve more attention.

On a fundamental level, if it's the arguments and ideas, and not different standards and traditions that the authors want included

I'm having a bit of trouble understanding this distinction. By investigating a question through different standards and traditions, we necessarily include different arguments and ideas. How can one study one but not the other?