Minecraft wiki entry for Best_biomes_for_homes, associated text: Blackstone, a necessary block for making furnaces and stone tools, is in abundance here.
Basalt makes for a unique building block.
An abundance of magma cubes means plenty of magma cream to be gathered, which can be used in brewing to make fire resistance potions. Considering the fire and lava immunity this potion gives, it can be very worthwhile to brew these potions considering the Nether's general terrain.
Ores generate at double the rate here than in any other biome, and they can be easy to spot due to using a netherrack based texture contrasting against the basalt/blackstone.