> I don't understand this about the Dutch people. So many old, granny bikes, that are so heavy, with steel fenders, steel stands etc. So heavy, inefficient.

Cheap, reliable, low-maintenance, unattractive to thiefs. When you drop your bike at the train station you don't want it to stand out in a sea of other cheap bikes.

And with bikes generally getting priority, the weight is likely less of a concern.