Why do Germans (also the Dutch too) like parclo's/folded diamond interchanges so much?
They became popular in the Netherlands during the 1970s. Most pre-1970 freeways were built with diamond interchanges.
Some of the advantages are less complex intersections, better suited for right turning traffic instead of left turning traffic for the heaviest traffic flow, and they provide a more natural deceleration when exiting the freeway. They also provide an advantage for cyclists and pedestrians because they can be designed in a way that cycle paths or service roads have 0 intersections with ramps instead of 2 with a diamond interchange. Or in another configuration: 1 instead of 2.