Even a 1 terabyte disc could be hugely useful in enabling piracy if it was cheap enough. You could share a colossal amount of music without the risk or effort of P2P.
Ironically the lack of a consumer grade system is bad for business. A lot of companies have remote offices with crappy connections that could be kept in sync with discs in the mail.
I don't think anyone has anything close to a ready-for-marketing 1TB optical disc. I do think that anyone who did would be perfectly happy to let the possibility of causing an incremental uptick in piracy take care of itself; they would, after all, be distracted by the probability of raking in enough money to fill Scrooge McDuck's swimming pool.
As for synchronizing remote offices, why not BD-RE? I can't imagine there being all that many companies at the intersection between having enough remote offices to care about synchronization, having those offices be in places without reliable backhaul, and needing to keep so much data in sync that one BD-RE 16x drive per office, and a relative handful of discs, would be an impractically large expense.
Start-up idea? (Minus the piracy of course). I'm not sure of the market but it could appeal to companies and professionals. Say for some reason you want the raw 4k render of Sintel but don't want to download hundreds of Gigabytes. Simply queue your download and then the data is snail-mailed to you on physical media. If you could chain a bunch of 128GB microSD cards together and then place in a sturdy plastic case, you could send terabytes in a single stamp envelope.
Ironically the lack of a consumer grade system is bad for business. A lot of companies have remote offices with crappy connections that could be kept in sync with discs in the mail.