Is the term Yekke pejorative? I think these days it has become a term of endearment. However, I'm not sure it was always that way.
Rav Schwab wrote, "We also refer to those yelidei Ashkenaz who, all of the sudden become ashamed of their traditions and their time-hallowed customs. Incidentally, we don't appreciate the poor attempts at humor that poke fun at their G-d fearing parents and grandparents as "Yekkes." The "Yekke" of today, like the "Pollack" of yesterday, belongs to the ugly pockmarks of a galus mentality, which became outdated some time ago. We are taught that "He who gives even one of his fellowmen a nasty by-name forfeits his portion in the world to come." Rav Schwab, Selected Essays p. 144.