Do we really want to talk about whether or not somebody should take the sperm of a completely different race? What is wrong with wanting your child to look somewhat like you? Also, our author only mentions only "Christian" and "Buddhist" spermia, not Muslim ones. Can we have a mullah to complain about discrimination, please?
Now, please don't get me wrong - you have all the right in the world to believe that DNA does not matter at all, you may get the semen for or simply adopt 20 kids of 20 different ... let's call it "ethnic backgrounds," that sounds pretty pc.
But, on the other hand, we have a Jewish tradition that dates back thousands of years and includes the duty to marry one of your own if at all possible. That is not discrimination. In order not to discriminate, should I have one wife from each race, so as not to discriminate? That seems to be the idea here. Or should I say I do not care about someone's ethnic background? That would be lying to myself and others - as a few authors above me already posted: "Jews are...""the most ethnocentric people on the face of the earth."
Now, will somebody who believes that we are so, and whether nor we are in reality is irrelevant here; will that person, upon meeting a Jewish person think: "Well, that person is Jewish, but could still be the father of my children."?
Or rather something along the lines of: "Well, the Jews are ethnocentric and I'd really like children that look similar to me, anyways."?
Which reminds me, to get to Jewish humour, of an old joke:

A Black man comes to a Rabbi in New York and tells him: "I have read about Judaism a lot, I have talked to many Jews and I have thought about all this I a lot - Rebbe, I want to convert to Judaism!"
The Rabbi looks at him and says: "Don't you have enough problems already as a Black man in New York?"

I think the joke speaks for itself. Defining humor in serious terms is something I will not do in the middle of the night. All I can say is that someone who doubts the existence of Jewish humor like our anonymous above obviously has no idea what he is talking about.

Good night and Shalom from Bochum, Germany