They probably just lost the ability to build it, or the source code can't be found. Happens quite often. 17 years is a /long/ time to maintain build systems and remember where you put the files.
Redundant backups are especially important for software companies. It's scary to think how many startups give all cofounders and developers admin access to everything. It helps that git is distributed, but it's not hard to imagine a scenario where a ticked off former employee wipes everyone's laptops and deletes the hosted source code.
Even if you don't update the mirrors regularly, it's good to know that you have some copies of data in BitBucket/GitLab/Heroku/Google Drive.