HaKatan, you are quite correct that the Brisker Rov had a much more hardline approach. So hardline that he also said one must not vote in state elections. The vast majority of the chareidi israeli community that I am part of follow the Gedolim who have a less hardline approach and allow voting. The Chazon Ish although allowing voting, also was well known for his strong opinions on the medinah.
And you are quite correct that both of them were greater than my grandfather. However there are many Gedolei Torah (who lived in EY) over the last 80 years who have the approach I described.
They include:
Rav Isser Zalman Melzer zt’l
Rav Yosef Shlomo Kahaneman zt’l
Rav Shlomo Zalman Auerbach zt’l
Rav Chaim Shmuelevitz zt’l
Rav Naftoli Horowitz (Bostoner) zt’l
Rav Ovadia Yosef zt’l
I am quite sure that none of the above would say that they are zionists in the way the term is used today and they would all consider themselves chareidi and yet each one, in their own way, used this day to thank Hashem for his precious gift.
I am told that throughout Rav S.Z. Auerbach’s life, Yeshivas Kol Torah did not say tachanun on YhA out of respect for him.
And I am sure no one had the chutzpah to go up to him (except maybe a Katan) and tell him he is deluded and he has been fooled by the zionists.
Similarly, despite the fact that he stood down with regards to electricity on Shabbos out of respect to the Ch’I, he never did with regards to this issue. He therefore held that it was acceptable for a Chareidi to hold a different view.
So HaKatan, while you are welcome to follow your own Gedolim, there are enough Gedolim within the chareidi world to support my approach.
Those Chareidim who would like to grab the opportunity to connect to HKBH and thank Him for the constant kindness he bestows on us are welcome to follow that approach.