The only anti-Patrick argument that hasn't been fully retorted is why doesn't he borrow fiat at a cheaper rate and convert it to bitcoin?
Why borrow at all? If he's making a narrow profit margin, why does he bother taking all the risk? If he's making a decent profit, why not use that profit to pay down debt?
Risk - by keeping all business in BTC there is no exchange rate risk.
Only an idiot would pay 100% APR to short with zero leverage.
Ideals - helping the Bitcoin community. This also has value in itself.
People convincing others to invest in something that looks exactly like a scam does not help the Bitcoin community one bit. The community was worse, more acerbic and heavily divided, before Pirate defaulted than after.