Rabbinical authority is not biblical?

Many people these days say that the Rabbi's have influenced Judaism to much. They want to follow the Torah and not made up rabbinical stuff right? Well following the Rabbi's is following the Torah:

Deuteronomy 17:8-12 from the Artscroll Stone edition:

17:8 If a matter of judgment is hidden from you, between blood and blood, between verdict and verdict, between plague and plague, matters of dispute in your cities - you shall rise up and ascend to the place that Hashem, your G-d, shall choose.
17:9 You shall come to the Kohanim, the Levites, and to the judge who will be in those days; you shall inquire and they will tell you the word of judgment.
17:10 You shall do according to the word that they will tell you, from that place that Hash-m will choose, and you shall be careful to do according to everything that they will teach you.
17:11 According to the teaching that they will teach you and according to the judgment that they will say to you, shall you do; you shall not deviate from the word that they will tell you, right or left.
17:12 And the man that will act with willfulness, not listening to the Kohen who stands there to serve Hashem, your G-d, or to the judge, that man shall die and you shall destroy the evil from Israel.