For some people, in some places still and throughout an all too often troubled history it has, sadly, been a very "big deal" indeed. It is the memory of this, and the residue we are still burdened with, that makes these things "touchy" subjects for many people.
I can't think of anything a person could go through that would make talking about whether or not Beethoven was black a touchy subject.
Unless if...
911: how may I help you?
Me: Beethoven just killed my family!
911: what does he look like?
Me: *height, body weight, age* and he was white
*a month later in court*
Judge: we're sentencing you to death!
Beethoven: NOOOOOO
Me: that's what you get for murdering my family you loser!
Beethoven: but it wasn't me! You have the wrong guy!
*A couple years later*
Detective: yeah, we got the wrong guy. Beethoven was actually black.
Me: NOOOOOOOOOOOOOOOOO!!!