I'll try to explain this (without any sources, sorry!) as best as I can as a practical matter in modern circles in the United States (and elsewhere).
First, many non-charedi Orthodox Jews in America maintain older customs.
Second, some "neo-Hasidic" (or "Modern-Hasidic") Orthodox Jews (I'm not using any accepted nomenclature, just calling it as I see it, but I'm referring to the growing trend of people taking influence from a blend of Hasidic customs and teachings) have also embraced the practice.
Still other have embraced the practice for the symbolism of 'Orlah (not taking fruit from a tree for three years), since both people and the Torah are compared to trees.