Some chumros have a place, and others are just that – chumros -but not halacha; certainly not what Hashem asked of us, and therefore a potential problem when those who follow them believe themselves to be better Jews than those who don’t, and act accordingly. (Because that is what often causes divisiveness amongst Yidden, that, and not the fact that the less machmir are not frum enough).
Once a charedi — the real deal, as in he was sent by R’ Yosef Chaim Zonnenfeld’s Beis Din — walked into Rav Kook’s beis din in Yerushalayim on some errand or other. He was upset to see that the beis din had modern trappings like filing cabinets and secretaries with typewriters and complained to Rav Kook that it says “chodosh assur min haTorah”. Rav Kook answered that he learns pshat differently. The bochur asked “how?” Rav Kook answered “Poshut! It means that we cannot eat grain from the new crop until the omer is brought!”