A short answer would be that, were it profitable, it would still be open. (Conversely, its replacement – SLS Las Vegas – is unprofitable but open, but for how long?)
Actual financial details of the Sahara's operations were always a carefully guarded secret. Even the purchase price Sam Nazarian paid for the property ($400 million) was kept under lock and key for years after the transaction took place.
About the closest the Sahara came to transparency was the March 2011 announcement that the hotel-casino would close, at which time Nazarian said, "While no final determinations have been made at this point, the continued operation of the aging Sahara was no longer viable."
Prior to this, bits and pieces had been, metaphorically, falling off the Sahara, culminating in the April 2011 shutdown of Speed: The Ride (still homeless, four years later). Sandy Hackett's Rat Pack Show and entertainment veteran The Comedy Stop were closed in October 2010. The duo had already been evicted from the legendary Congo Room when Nazarian closed it the previous February.
In truth, the writing had been on the wall for the Sahara ever since December 2009, when it closed two hotel towers, never to reopen them. (At the time, LVA reported that the Sahara buffet was "hanging in the balance," although it ultimately survived as long as the rest of the property.) Even with a reduced room inventory, the Sahara found itself unable to command rates higher than the $30 range and even offered some for $1 a night in Twitter specials.
The Sahara's atmospheric House of Lords restaurant was an on-again, off-again proposition during the Nazarian years and the addition of a tattoo parlor in the main lobby failed to deliver any financial miracles. Neither did the reinstitution of $1 blackjack or the only bingo to be had on the Strip. Once home-from-home to some of the biggest stars on the Strip (see Mike Weatherford's Cult Vegas, sadly the Sahara became the place where production shows went to die. Anybody remember ND's Fuego? Striptease The Show? No? We rest our case.