It's not like people condemning the choice of the name are unable to find the humor. We do find it. We are briefly entertained. Then we pause and ponder. Is it a good idea to use a negative stereotype in a joke? Don't we run the risk of confirming the stereotype even more?

We then find out that our answer to that question is "no". And we bring up the issue with other people.

There is no "inability to find humor" at play here.