There is a myth about the Shattering. It states that the Shattering was put into motion by one human, one that had seen the future. -- Anon Guest
Five hundred years makes all the difference. For Earth, it viewed all its sundry colonies as a form of backup. Not just for the Human race, but also for the data and knowledge the colonials took with them. Surely, they reasoned, the colonists would keep such vital information about their beginning days.
Of such reasoning, the Shattering was made. Human history was broken into pieces, taken to separate locations, and most of it has yet to be recovered. Vast swathes of culture and knowledge, gone because a single group of people thought it was 'backed up'. Every subsequent graveworld is a lost chance. Every lost seed of a new civilisation is another hole in Human history that may never be patched.
Humanity - the bits of it that made it through the gauntlet of colonisation to become their own model civilisation - has a great want of someone to blame. A singular soul who made an executive decision to do the bad thing. Such is not the case, of course. Negligence through laziness doesn't have one source, but that has never stopped a Human from seeking out a perpetrator. Ironically, the journey to do so involves numerous trawls through Terra's surviving archives, some suffering from The Shattering themselves.