That is not entirely true. It's a bit more complicated. Yes it is protected since the 1970s but it's more of an academic title. You needed to study something that is "mainly" of technological or scientific nature. Basically befire the Bologna reform every student in Tec. Unis/FHs did get the title Diplom-Ingenieur. So the engineer part was literally part of your degree. This of course also true in case you studied IT. So yes there are many who call themselves IT engineers also in Germany. However it's more of a philosophical question how much software development is actually engineering or rather craftsmanship.