While I don't have the rules to hand, I do know that some of them differ between German Bundesländer (states). So it is possible that e.g. Nordrhein-Westphalia (DUS) does not allow things that Hesse (FRA) or Bavaria (MUC) do.
However, much like other posters, here I am inclined not to give LHG the benefit of the doubt, but instead call this a simple cost containment decision.