It sure helps that the code is open source. However, there are some factors that still make it harder for other people to pick up a project - a lot of knowledg

It sure helps that the code is open source. However, there are some factors that still make it harder for other people to pick up a project - a lot of knowledge can be lost how the system works and has to be reverse engineered - which fork is the chosen one by the community and how will people know about it - branding might be unclear, can you reuse the name or should you rename your project