[probably_wrong]

By the time a train is delayed enough to be canceled the mandatory compensation applies anyway, and I'm not sure how much DB cares about bad press.

I can see the cancellations as a means of stopping a cascade of delays, but it's also true that doing so means the train won't count in the delay statistics for the remaining stops. If DB doesn't want people to accuse them of gaming the statistics, perhaps they should calculate said statistics in a way that doesn't directly benefit them when they inconvenience their delayed passengers even more?