The Stonecutter doesn’t let Quartz Stairs be crafted from Quartz Pillar Blocks but they can be crafted on a Crafting Table.

The Stonecutter does not present any options to convert the Quartz Pillar Block.

Edit: This issue also extends to Chiseled Quartz Blocks and also Quartz Slabs although it is not an issue with them as the ratio is also 1:1 with crafting.

Edit 2: Bug was not fixed in 20w16a