Getting the Kiddush Right & the Four Cups -- Talmud For Beginners

That's a very good question.

In short: Making a halachik ruling is implicitly saying that ultimately such is the 'will of G-d'.

How does the human being, who is subject to all the limitations of humanity, synchronize their mind with G-d's mind - a mind that is supernal, infinite and omniscient?

The answer is, that human intelligence is not sufficient. The cleverer you are does not necesarily mean the closer you get to G-d and His mind. Other tools are required to tap into the Divine mind and conscience - and humility is one of those tools.

So, it seems that Beis Hillel's behaviour indicated that they were better equipped to accurately dictate the will of G-d.