147 is probably just trolling. I think he doesn’t actually believes what he writes because he seems to never miss an opportunity to extol celebrating Zionist holidays yet never responds to any statements made against his position. This is known as trolling.
But if he does believe what he’s writing, he’s probably also not interested in (anyone) knowing that the Chazon Ish said that “mi hu apikores shomer torah uMitzvos? Kol mi sheChogeg es yom haAtzmaut..” Perhaps their “Yom Yerushalayim” is not as bad, but who knows?