In Core & UM, the DEFINEs necessary to enable the DruidDomain_x_Allowed are on Internal. In APG, they are on the Nature's Bond ~ Druid Domain ability - which also sets them all to 1. To actually use the APG-style flags in DATA, one therefore has to go through and BONUS all the domains not wanted to 0. The Core & UM design is easier to use (as one can just grant the domains directly rather than via Nature's Bond ~ Druid Domain and then BONUS the domains you want to be available).
Anyway, consistency of implementation is a goal in itself