Value, respect, and strive for diversity in editors

You say "At the German Wikipedia it's relatively normal to block people with the reason "no discernible intent for encyclopedic collaboration". For the English Wikipedia this is an unacceptable reason unless a user is actually vandalising." This seems to be a cultural difference. It is doubtful such a no-nonsense approach would be generally supported on the English Wikipedia. If nothing else, it involves jumping to conclusions rather quickly. People often play around a bit before they get down to work. Assume good faith is a sound approach.

I was thinking of users with a few thousand edits who are basically just disrupting talk pages.