I don't disagree with this at all, but why is it a white/non-white thing? Like if I belong to a minority group I automatically can understand how, for example, black people feel in america? I just think there's no reason to single out white people. You could say "those not belonging to the same group".
I actually agree with the OP in that I wouldn't want to be the only white guy in a room full of black/brown/asian people so I'm not sure I fall on a particular "side" of this conversation. In fact, I'm not even sure anyone has argued against the idea that diversity is important (for POC in particular or not) though people seem to have built up that strawman here - a fallacy not atypical of a typical undergraduate Arts class I might add.
I'm not really sure I fully understand your second point though as it seems nearly identical to the first. One does not have to experience something to understand it. Perhaps on an individual level I cannot fully comprehend one's psyche, but to suggest that, on the basis of race, one could not possibly understand why something is true is absurd and prejudicial.
No. I can't. And maybe language is insufficient to the point we're discussing, but you know what I'm saying is true and just about everyone does, even when phrasing it in a sentence may be difficult.
Someone says, "this is what I experienced, this is how I grew up, this is what I lived through, and so this is why I do this now."
You say, "okay, I understand why you do this now."
They say, "you understand what I just told you as information, but you don't really understand why."
Look. Whether at this point we're talking about the experience of being radicalized, or the experience of living with real, gut-gnawing hunger, or living through a genocide, it's all someone else's life that you haven't lived and someone else's experienced that you haven't shared. Now matter how you deploy language, it's arrogant, insulting, and utterly infuriating to suggest that being told about it by other people - that simply hearing the information as a story - gives you the same level of insight into the experience as someone who's lived it. That claim is simply beyond the pale.
So, sure. You may "understand why." But you'll never understand why. And we all need to acknowledge that. Even when we're arguing with someone we disagree with.