The assumption is that the people shadowmining XRs are using Corsair ID to protect themselves from DTR.
As a rule of the thumb: Player factions do not exist in the canon game environment.
This means that specific factions like DTR have no right creating laws which benefit their specific faction. In anything, laws should apply to all Corsairs equally.
Also, it is funny how DTR complains about indies mining relics. Why wouldn't they? If their ID allows them, let them. I still remember DTR using their Zoner alts to supply their POBs, sometimes even using outcast bases to do it, so this move against indies is hypocritical at best, and malicious at worst.
Seriously, it is not metagaming when you fly an indie ID to mine relics for whatever reason. It is, however, powergaming, if you seek to prevent them as the OF of the same faction.