It seemed like a good idea at the time.
It took almost a century to build it, the planet that was its mother relatively smaller and afraid for its own life. What better way to protect themselves than to build a machine that would devour any threat that may or may not come their way?
And what better way to eliminate the threats than by using null matter, the very antithesis for life as they knew it?
What they didn't anticipate was that sometimes, a creation can have a mind of its own. When given the idea of devouring anything in its path that seems a threat, it needs certain parameters in order to figure out on its own what makes a threat.
And if none are giving, it usually means that it has to develop its own.
Expectantly, their desires were met. The new tool, dubbed the Beast Planet for its hunger, was effective and did the job.
What was unexpected was that it would view its mother planet as its first meal, its first threat. What was unexpected was that with the nourishment, it learned from its mother and created its own children. And what was unexpected was that it would view anyone - and everyone - as a threat to be made into its next meal.