Why do we pasken like Beit Hillel? In fact we see in the Gemara that individuals followed the psak of their Rabbi when another individual may have followed the psak of a different Rabbi with diametrically opposed end products. The Talmud on daf 6 gives us a fascinating look at the history of why we follow Beit Hillel in most situations:-
ומי עבדינן כתרי חומרי והא תניא לעולם הלכה כבית הלל והרוצה לעשות כדברי בית שמאי עושה כדברי בית הלל עושה מקולי ב”ש ומקולי ב”ה רשע מחומרי ב”ש ומחומרי ב”ה עליו הכתוב אומר (קוהלת ב) הכסיל בחשך הולך אלא אי כב”ש כקוליהון וכחומריהון אי כב”ה כקוליהון וכחומריהון
[The Gemara poses a question:] But do we adopt the [respective] stringencies of two [authorities who disagree on a series of issues?] Wasn’t it taught [in a baraita: The] halakha is always in accordance with [the opinion of] Beit Hillel, but one who wishes to act in accordance with the opinion of Beit Shammai may do so, [and one who wishes to act] in accordance with the opinion of Beit Hillel may do so. [If he wishes to adopt both] the leniencies of Beit Shammai and [also] the leniencies of Beit Hillel, [he is] a wicked person. [And if he wishes to adopt both] the stringencies of Beit Shammai and [also] stringencies of Beit Hillel, with regard to him the verse states: “The fool walks in darkness” (Ecclesiastes 2:14). Rather [he should act] either in accordance with Beit Shammai, [following both] their leniencies and their stringencies, or in accordance with Beit Hillel, [following both] their leniencies and their stringencies.
The Talmud goes on to say that this was changed after a Bat Kol (a heavenly voice) proclaimed that we should only follow Beit Hillel.
The fascinating post script in the Talmud comes when we are told that Rabbi Yehoshua does not pay attention to a Bat Kol. Does he allow us to follow Beit Shammai? Or, does he say we should follow Beit Hillel? A point which is not discussed in our Talmud?
Rabbi Yehoshua’s position is famously stated in Tractate Bava Metzia in the case of Rabbi Eliezer who made various miracles happen to prove his halakhic decision was correct but even after a heavenly voice confirms this, Rabbi Yehoshua states that “Torah is not in Heaven”. It is people who decide the law not a heavenly voice! (cf my previous post about the role of human beings in the holiness of Shabbat!)
Shabbat shalom from the Holy Land.