Here's why:

* Non-metallic nature: Sulfur is a non-metal, and non-metals generally have poor electrical conductivity.

* Covalent bonding: Sulfur atoms form strong covalent bonds within its structure, which tightly hold electrons in place. This prevents the free movement of electrons necessary for electrical conductivity.

* Absence of free electrons: Unlike metals, sulfur does not have free electrons in its structure. This limits its ability to transport electrical charge.

In contrast, metals are excellent conductors of electricity because they have a "sea" of free electrons that can easily move throughout their structure.