i'm glad that at least your other days were fun. I've had a bad experience also at a seminar, in part through my own misunderstanding, so while i don't doubt those folks acted like jerks, some things you might want to consider:
1) some places wear hakama from the lowest kyus up...so they may not be your seniors, and may be as lost in how to behave as anyone
2) some large/big name seminars draw non-English speaking participants...they may not understand when you talk to them
3) some of the folks on the mat may have been working with or around VERY senior partners you might not recognise, and are just trying to keep an area clear for them, which you would want to do if you knew who they were
4) some folks might be working with someone they know takes terrible ukemi, and are trying to lessen your chance of getting sideswiped
5) some folks don't behave well in public...a good chance to practice getting along with difficult people.
as for treating women better....i would disagree, but that is a whole other topic. Glad you had a good time overall!