They belong to an arrogant and near all powerful organization that's shaped them from youth so they would see the world from their narrow perspective.

An important thing is that the Tower doesn't recruit much. They let women come to the Tower to be tested. It goes without saying that most of these women who decide to go get tested isn't fundamentally opposed to the the ways and worldview of Tar Valon. They wish to join that organization. All of them but "wilders", who have no choice and are found and trained by the Tower. That's why the rest of the Tower dislikes wilders so much. Unlike them, they never dreamed of joining the Tower, this was pushed on them, and many don't have the right frame of mind to think the way the other AS do. This is what happens with Nynaeve. She didn't come admiring the WT, she came hating it and seeing flaws upon flaws in sisters like Moiraine. Nynaeve has a very personal vision of what AS should be that she developped around how she sees herself and how she reconcile her personality with becoming a sister. Unlike most she never got the years of training to "reshape" her views. Egwene is more like a sponge - her motto could be "When in Rome, act like the Romans". She did that everywhere she went, though she's becoming more and more critical as she wizen up, and is more open now to questionning her worldviews. Elayne is also more conservative, though her views on AS got influenced a lot by Nynaeve's, and by her role as Queen (she now tends to see the benefits of channellers with the eyes of a Queen rather than an AS. She lost track that the WT must remain neutral and can't favour a nation over the others - she'll no doubt be reminded of this by Egwene soon). The same might have happened to Egwene, had she not gotten separated from Nynaeve so early, but instead it's a mix of Moiraine's independant streak and Siuan's traditionalist and political-minded views that dominates in her, with a remaining streak of TR practical thinking.