Diversity hiring in adobe

Why does Adobe only hires women for new grads? They came thrice in my college for placements and hired 30 girls ,10 for mts at package of 44l(18base) They weren't even the smartest girls,let alone being the smartest in the whole batch. It's not new, they have been doing this from past 7 -8 yrs in almost all the colleges including old iits . What's the logic behind this? A lot of companies like apple ,natwest ,Tesco do but not in all colleges or not from the past decade