User blog comment:Saratje/PC release date explained - Skyrim: Dragonborn DLC/@comment-192.127.94.7-20121203154610

This article is wrong. Hearthfire added new scripts, areas, models to the game. It was no different then Dawnguard, just on a smaller scale. It costed money, had a simplistic quest line and was extremely fun. It was Downloadable Content.

The reason they give 30 day exclusivity to Xbox 360 is because of piracy. They don't want to hurt Xbox 360 sales because of people pirating the DLC on PC. It has nothing to do with Microsoft or Bethesda hating their fans.

Many people buy the game for Xbox 360 but also pirate the game on PC. Many people also have a 360 but would otherwise just pirate the DLC to save 20 bucks for "pixels and bytes". If I owned Bethesda I would do the exact same thing. This is a company that produces good content and wants to be paid for it.

If you are butt hurt as a PC user when you already have access to over 10 TB of free content on Nexus, then please uninstall the game and boycott their mods.

tldr;  Pirating and article is wrong.