1. The article is not antisemitic but is anti-Hasidic.
2. The Google definition of “insular” in this context is “ignorant of or uninterested in cultures, ideas, or peoples outside one’s own experience.”
synonyms: narrow-minded, small-minded, inward-looking, parochial, provincial, small-town, shortsighted, hidebound, blinkered
It sounds pretty derogatory to me. People should know about other people’s cultures and ideas if they are going to live among them. It will help to alleviate friction and will enable them to better argue their positions (this is found frequently in the Gemara – lesheetatcha).
Having said that, the Hasidim interviewed did not defend the eruv properly. They should have pointed out that someone who is not looking hard for it will not even notice it.