Current event droprate is too random or too low. I've been active on a normal level* this event and didn't get one event girl yet. Last events I've always been able to get both with same or even less activity.
This kind of randomness frustrates players. In addition you get new content every 3 or 4 weeks... in conclusion this means for me: skip most of the events (frustrating), play the game every 8-12 months (to avoid some lore breaks).
*normal level: f2p, 40 girls (missed some events due to holidays
), 23.3m gold, 7/12 event quests.
Edit on 8th Aug, Tuesday: 8/12 event quests.