Maybe because games as a genre are really different from the tools most open source communities are centered around? Games contain a lot of art (subjective, mad

Maybe because games as a genre are really different from the tools most open source communities are centered around? Games contain a lot of art (subjective, made by a few/single persons), lot of authority is needed to hold it together, and the product is mostly not something to be refined for years but a one-big-release affair which is would only be used/played with for a limited time. The same way how you couldn't open source a poem or a book - the most you can do is be very community-based, like how most modders - akin to indie game developers - do. Are there any major open source game development besides maybe OpenTTD or Spring (which are more like frameworks and less of a games themselves)?