Another nit, the "abandoned" part is the one that was open sourced a loooong time ago. Since then, it underwent a ton of changes but yeah, it's within Facebook. So, not abandoned at all, but not available outside.

The main issue (as usual in big companies) is the large amount of inter-dependencies with internal systems. Scribe as-is today doesn't make much sense outside Facebook. And yeah, it could be cleaned up, mock the internal services and OSS it. But that's a lot of work, both doing it and maintaining it. And having all those mocks, etc "wouldn't be Scribe as-is either"in terms of how e.g. it scales and so on.

In any case, the storage (LogDevice, https://github.com/facebookarchive/LogDevice) which is a large part of the system was open sourced a while back and... sadly it went again into "not-maintained OSS".

Finally, you can get a similar-ish system working with OSS tools (e.g. fluentd + Kafka) that will also scale quite well and which IMHO can also made to scale to Facebook-size levels. So, the incentive is there, but there are OSS alternatives already available :)