Agreed, but when you consider that SR charges 150.00 bucks to be a vendor, charges 6 percent to have access at your escrow money and another 5 percent to hedge the vendors bitcoin. Along with other data that they couldn't get or see, I would argue that SR is bringing in much more than 6k a day..
It is possible the researchers had some error in the their analysis but lets assume the profit is on the ORDER of $6K. i.e. it might be $12K or it might only be $2K. But it is very unlikely that it is $60K or $600K a day.
Pirate's interest obligation is $50,000
per day (and more like $75,000 per day at the Bitcoin peak). Even IF SR generated $50,000 per day in profit the owners certainly wouldn't give it all away as interest to third parties. Even IF SR generated say $100,000 per day and for some reason had to use Pirate @ 1% per day (and give up half their profit) they could pay down the debt in a mere 10 weeks and thus no longer need Pirate.
Of course you also need to consider that the 1% per day is what Pirate was paying
lenders gamblers. If it was a business obviously he isn't doing all the work and paying out 100% of net profit to the lenders. Say he decided to split it 1/3 to himself and 2/3 to lenders. That puts the profit required at more like $75,000 per day and ~$125,000 at the Bitcoin peak.
Starting to see that while the researchers may not be able to say down to the penny exactly how much profit SR operators made the cashflow of Pirate's operation is so much larger that even using the most unrealistic assumptions you can fit that square peg into that round hole.