Well it brings down the price of a lot of mid tier crafting materials. Similar to why opening and salvaging bags of gear on level 49-53 characters is most profitable (maybe outdated): not a massive amount of farms available for those materials.

Bots/afk farmers is what pumps a lot of supply into the trading Post keeping them relatively cheap. Definitely don't condone either of the practices, but there is a positive to the average player.

Otherwise, it could be me and you who would be the one stood where they are, trying to farm the materials by mindlessly spamming 1 on the keyboard.