score:7
The point was to give a concrete definition of "holiness" - namely that God was "set apart," i.e. holy, and God wanted his people to be "set apart" from the other nations.
These vestigal practices mainly were a symbol of a greater concept - that as God's chosen people, they were to be different / separate from everyone else.
The opposite of holiness is syncretism - mixing in religious practices from outside Israel into the worship of YHWH. He would often say of himself "I am a jealous God." He would not share his glory with any other.