The peoblem, and it already exists on Long Island in The Five Towns involves the schools. Hasidics send their kids to Yeshivas as is their right, but they run for and win control of the local school boards where they can limit spending, lower school taxes, direct spending like repair and transportation to fellow Hasidics and create a sense that the schools are in need of improvement, prompting non hasidics to sell, oftrn for cash to other hasidics. The animosity is not simply one of appearance and eruv wires but of totally changing a community via legal but disturbing means.
That’s it in a nutshell, as you say. I am Chassidic, though I live in Israel so am not involved in this. I think some hard-headed diplomacy and some tact are what’s needed on both sides. The Rockland County residents do have their legitimate grievances, and the Chassidim can accomplish what they need to thrive without a hostile takeover of the whole Rockland County. But this ad and the knee-jerk reaction to it are both going to make the needed detente harder to initiate. Both sides do have their respective leaders, and the job of leaders is to practice the art of the deal for everyone’s benefit.