There are people who download and play content for version 2.0 and earlier, so you would not be a rare instance. The game being open-source means builds going all the way back to the original Halloween demo can be found somewhere online.
For some, it is about experiencing the history of the game in an authentic manner. For others, it is the challenge of building a level that tries to meet 2.2 standards without things like slopes. Still for others, there are a lot of older levels and other content that have never been updated that can then be played. There is no expectation that everyone be on the same build but take note that the latest is recommended for new Addons & More content.