I have always found it curious that we find ourselves (through the prism of Jewish law) to be stricter in the observance of Rabbinic Law than Torah Law.
וחכמים עשו חיזוק לדבריהם יותר משל תורה
And the Sages reinforced their statements [even] more than those of the Torah
There is a clear concern that we, as individuals, will think that Rabbinic Law is in some way less important (even though the Rabbis are given their power from on high) and we therefore need extra stringencies in order to safeguard these laws.
Maybe because it is counterintuitive it is necessary!