Iniquus Passu?

Is the pari passu clause found in sovereign debt contracts really about "pari passu"? Is the clause really a guardian of creditor equality? Should it be? Perhaps debtors and (non professional litigator holdouts) creditors would be much better served if pari passu was in fact a promise of inequality, not equality. Interestingly, this is not just abstract philosophizing. Empirical evidence actually shows that the market has in recent times been busy embracing versions of pari passu that indeed promise inequality and openly ban broad equality. Vast swaths of the sovereign debt market loudly proclaim that they want pari passu to be a contractually sanctioned guarantee that creditors can be treated differently. Most telling, the version of the clause that makes the most aggressive promise of equality has all but been ignored by market pros (even as a borrower as big as Italy was using it; this country too later relinquished such pari passu version). It seems quite obvious that the sovereign debt market does not have the hots for pari passus that make explicit promises of broad equality, while quite liking pari passus that allow for unfettered inequality. Which makes New York judge Thomas Griesa's ruling for ratable payments in the Argentina case the more puzzling: when the market appears to be running away from equality, why impose the widest possible form of parity?