I suspect they just refer to "black box practicality" here. As in they have a nice library for FB developers and the API is simple enough. And if something goes

I suspect they just refer to "black box practicality" here. As in they have a nice library for FB developers and the API is simple enough. And if something goes wrong the FB person can contact the author and they will fix it for them. I guess that's practicable enough for them. I was looking more for "I can understand/implement/debug it myself" practicability, avoiding black boxes. Even in the FB case there is the bus factor of course. When the author at some point moves on to greener pastures they can only hope that it still fits into the brain of whoever replaces him.