Bek

Because larger mod projects aren't a job (get paid) and people create/produce the content on interest and drive alone. Some people lose that interest/drive over time due to whatever reason.

I'm really thinking about picking up where they left off.

Content specific to a creation is a waste of time. Create/release content piece by piece then tie it all together after. At least this way people can enjoy the content even if the project is never fully finished. Plus if you have all the core stuff done and released, most you have to do for the mod then is just add in the SP specific scripts/npcs/bosses cause all other core content is done.