The problem with the current immigrants is, that half of their brain is occupied by religion. Another problem is, that half of their population is not allowed to do anything else beside breeding and taking care of children at home.
Chances of them contributing in a positive way to the German community are around zero.
I'm not muslim, but I'd like to take the devil's advocate position here. Turks are part of the German society since sometime in 1990 (maybe even before). Even though I'm a Greek, some of my best friends are Turks that (wait for it) are scientists, as children of poor migrates! Almost none of them is religion oriented anymore. Science tends to transform people to a-religionists at best (we had this conversation about 3 pages ago).
As I wrote above, incentive is a very strong paragon towards success. No matter who you are, where you come from. As I spent half of my life in the university, I've often met colleagues who were hostile against people of certain origin. It's alright not to like everybody; but you shouldn't berate them before they have the chance to prove who they really are and what their brain capacity is.
I was in awe many times in my life by such paradigms; take my word for it (or rather Alan's words):
