Awe, Joy and Routine
The Baal Shem Tov taught that in earlier generations, the awe of the Yamim Noraim shook people up and inspired them to improve. Therefore, the judgement of each individual was sealed then. The heavenly court would find every Jew in a state of intense teshuvah, and be able to render his judgement favorably.
In later generations, people were unable to change from a place of fear. Thus, the final judgement was postponed until Hoshana Rabba, and even Shemini Atzeres. From a place of joy and dveikus the Jewish people could do teshuvah and be favorably judged.
But the generations got weaker. Strong emotions fail to take hold of our hearts and don't make an internal impression. What works for us is a small, consistent change over a period of calm routine. In his great desire that Jews be judged favorably, the very last generations receive an extension until Zos Chanukah.
In later generations, people were unable to change from a place of fear. Thus, the final judgement was postponed until Hoshana Rabba, and even Shemini Atzeres. From a place of joy and dveikus the Jewish people could do teshuvah and be favorably judged.
But the generations got weaker. Strong emotions fail to take hold of our hearts and don't make an internal impression. What works for us is a small, consistent change over a period of calm routine. In his great desire that Jews be judged favorably, the very last generations receive an extension until Zos Chanukah.
Harav Moshe Wolfson ztz'l