Do you not realize how discriminatory this statement is? Can you imagine making a similar statement about a different ethnographic group?

Apparently not. As a white guy I don't think it would really be appropriate for me to make a similar statement about other groups.

On the face of it, it doesn't make much sense that your ethnicity should affect the truth value of your statement. Being a certain ethnicity can make you more likely to have the requisite experience for certain perspectives, but it can't actually alter the reality of an argument.

Even if you make a generalization about your own ethnicity, it's still a generalization that's not particularly helpful. If an argument is considered inappropriate because it targets a different ethnicity and is also an unhelpful generalization, it does not suddenly become helpful when retargeted to the speakers' own group.