Religious zealotry is not new to the strictly Orthodox, but the trick is always to know where to stop. Adding more rules, more boundaries, is easy. In days gone by, the great leaders of Orthodox Judaism were those able to ease restrictions, to limit new halachic stringencies — without losing their authority with the masses and with other rabbis.
What we see today is the result of a leadership vacuum. The rabbis are led by fear. They are afraid of being portrayed as not religious enough, afraid of being thought of as not serious enough. Thus, not even a responsum of Rabbi Moshe Feinstein — a halachic giant from the last century — permitting mixed seating on public transportation can convince the trembling rabbis of today. Rabbi Feinsten’s opinion was spread by opponents of the new campaign, printed on leaflets and sent by email, to no avail.
The push for segregated buses is also yet another proof that, without very strong opposition, extremists get what they want. Strictly Orthodox passengers did not shy away from harassing other, less convinced and less obedient passengers, and their deeds were left unpunished. When the foes of “separate seating” arrangements called for Jerusalemites who were less extreme to defy this unreasonable dictate, no one answered.
Thus, by the sheer power of numbers and enthusiasm, the Charedim are slowly but surely winning this battle. A battle with no commander-in-chief, and no strategy. Just many junior officers running around and winning meaningless victories.