Who me? Are you seriously asking if I didn't know blackface was offensive? After what I wrote?
Then again you so seem to be ignoring the misogyny.
I can't explain but any more than I, and others, have. If you don't get satire, or the fact that it, like almost all comedy, ages very badly, then we will continue to post at cross purposes.
Put as simply as I can:
It is racist (and misogynist).
It was intended to be.
It reflected unpleasant but somehow accepted opinions of a proportion of society of the time. Not the same people all the time, obviously!
It was intended to be uncomfortable. And all the 'ists' you want to throw at it.
Now, with changing social mores, looking back even that deliberate act is itself all the 'ists' you want to throw at it.
But still some people will like it. Either for it's surface humour or for it's more layered social commentary.
I get that you don't like/see those multiple facets of it. But, whilst I don't like it now, any more than I did then, I do see that it had its own internal logic and was lampooning society, and that doesn't make me stupid or racist.
What it does show is that most topical humour doesn't survive it's immediate environs.