It's to be expected really. There's an inordinate amount of new people, and a large percentage of them come on here to:
(a) whine about how they/their child got cut from a group
(b) try and dig up dirt about the Greek system, and find how often we beat our NMs and make them stand naked on the street corner
(c) try and figure out how XYZ picks their new members
(d) pull any other ridiculous thing you can think of that stirs up trouble
All you can do is continue to post. If your post is good/logical/non-whiney, people may not agree with it, but they'll respect it. Continue doing that and you'll stopped being called such very hurtful names.
Disagreeing with one of the older members might make you appear like fitting into a-d, especially since the majority of them
kinda know what they're doing. If you really disagree, stick to your guns, DON'T pull out a shallow, silly attack and be willing to admit you might be wrong. Many of them are.
P.S. Note my really tiny number of posts. I'm in the same boat as you, bud.