text: That's the way almost all addressnodes have been imported the Netherlands. 
  Check this one:
  http://www.openstreetmap.org/#map=19/51.66491/5.29637
  The nodes have probably been put in line by the person  who did the import (or by somebode else).
  Part of the problem is that all that house numbers are in reality very close together near the entrance of the building. There is some sort of agreement that the node for the address should be put as close to its real-world position. That is impossible with these kind of buildings, hence the distribution over the area.