So Much Holier than Thou, she'Haval al ha'Zman
There are theological issues here that I don't want to get into. Let's focus a little on the halachic side. Part of the rationale for this new stringency is the proximity of the neighbourhood to Petah Tikva. In Petah Tikva, Shabbat comes in earlier than in Bnei Berak. Therefore, they concluded, we can do the same.
But Shabbat comes in early in Petah Tikva for a historical reason. The city was established by generation-old Jerusalemites who dared stray beyond the walls of the Old City. In recognition of that connection, Petah Tikva decided to follow the Jerusalem custom. By appropriating this custom for Bnei Berak, a city with a shorter history, it is being debased into just another way of making life difficult.
In the Sixties and Seventies, one of the hot topics in rabbinic circles was how to observe Shabbat in outer space. One opinion was that an astronaut orbiting the Earth must observe Shabbat every seventh orbit. This would translate into once every three days, I think. Rav Menahem Mendel Kasher wrote a harsh response (in his periodical, Noam, reprinted here). His main point was that the essence of Shabbat is its time. Shabbat is the seventh day. No less and no more. Once you start stretching those boundaries, it loses its meaning.
Of course, another fundamental aspect of Shabbat is its difference from the rest of the week. You must cease from work on the Sabbath. But you must work the rest of the week for that to mean anything.
I couldn't find the article on Haaretz.com, and couldn't link to it on Haaretz.co.il. If anyone can provide the link, I would be grateful.