I was reading your post and couldn't help noticing you saying that these ladies were Qatari. Have you seen their passports? Are you sure they were Qatari? I have many Qatari women friends and i know them to be very kind and polite.
I can assure you that not all ladies dressed in abaya are Qatari. On top of that, Qataris travel first class most of the time, so they'd sure have their own check in counter.
Don't assume straight away they were Qatari, because most of the time they aren't. Was there a man with them? if there wasn't, then 100% sure they were not Qatari.