I strongly disagree. Stromberg is pretty much the perfect pick to invalidate your claim. Of course there's lots of negative examples, too, but that also applies to British and, to a much much larger extent, American humour. Be picky and you find quality, for every taste. I'm a bit surprised though as I remember reading your strong opinion against political correctness (which I share).
another speech: Edward R. Murrow (David Strathairn)
We could easily spin this debate to make it last for hours and go epically off-topic...
Stromberg et al.
might be politically incorrect, which I don't mind, but that doesn't make it automatically funny. I don't see how it's so brilliant. You mentioned Britain and USA. Well, their versions of Stromberg are a thousand times better and funnier than Stromberg. There are of course plenty of examples of brilliant German comedians. The classics Helge Schneider, Hape Kerkeling, Harald Schmidt (though he's at times a bit too rude even for my taste...). But as a whole, Germany fails at being funny. It wins at a great deal of other things, I fucking love this country, but it's just not born to be funny.