I find it very strange to see german words and abbreviations intermixed with the english of the underlying langauge.

I see you know what I mean :). Usually, the more formal knowledge and experience a programmer has, the less he will use non-English language in his code.

I suspect that there are relationships between cognitive models that are beneficial for computing (...) and cognitive models that are beneficial for the language we speak

I do think this is quite true. The language we use shapes our thoughts. Another example are Indian languages; I've heard Hindi has a rather mathematical structure as well and I definitely can see it in the Indians that I know. These are all just tendencies, of course. Just as growing up in a family of musicians doesn't make you a musician automatically -- but in a lot of cases, it helps.

I'm not sure about the disproportionate number of German speakers in computing. However, what does come to mind is that we both have a strong history in philosophy (as diverse as Luther, Kant, Nietzsche and Marx) and in construction of calculation machines (lots of people messing around with these in Germany, e.g. Philipp Matthäus Hahn in the 17th century, and up to Konrad Zuse, who built the first binary digital computer).