I use this like a cliche these days, but I'll say it again.
The way you perceive others is often a reflection of yourself.
I've seen many Koreans who easily take offense to some of the most insignicant situations. For instance, I've seen my parents interpret some little joke as a "racist remark" and take offense. What I found interesting was that they often make some of the most racist comments I've ever heard in my life - especially against African Americans.
So there is a good chance that if you took offense at such a simple joke like this one, it is likely because of your thinking. As far as I see, Czar did not intentionally mean to offend or discriminate anybody. He just found it funny so he posted it. You assumed his intention. So the problem is with you, not Czar.
I learned that 95% of the time I found anything "offensive", I had no good reason to be offensive. I just thought that they were offensive for no apparent reason. Learn to fix yourself. It is very powerful and will save you lots of unnecessary trouble in your life.