Jones was not QDed from UFC 182 because at the same time NSAC presented UFC with his test results, they also opined that they had overstepped their bounds in testing for cocaine, because they only are chartered (by the UFC) to administer up to WADA standards, and the WADA protocol does not include OOC testing for recreational drugs.
Both of the headliners at UFC 183 failed drug tests. One tested positive for two AASes. The other tested positive for cannabinoids. Guess which fighter won the judges' decision?
The UFC is owned by Zuffa enterprises. Zuffa enterprises is two rich kids, the Fertitta brothers, playing with Dad's money. Dad, an entrepreneur and casino owner, died four years ago. Which, for the Fertitta boys, is a good thing, because they no longer have to answer to Dad's margin call. And it's a bad thing, because Dad is no longer there to cover the boy's markers when they're on a losing streak.
The UFC is on a losing streak. And strapped for cash. The last UFC that did a million PPVs was UFC 100, in 2009. Last year, Zuffa's profits were off by 40% because the UFC did so poorly. The UFC did so poorly because too many top fighters got injured, too many top fighters got popped for PEDs, and one headliner missed a title fight because he got lightheaded during a routine weight cut, fell, and cracked his noggin. Which left a flyweight title match as that night's headline attraction, and the flyweights just got no gate.
The UFC's biggest PPV of 2014 barely broke 300,000. The two biggest PPVs of 2014 (including the 300,000 viewer event) both featured Rhonda Rousey. The only three truly bankable stars the UFC has under contract at the moment are Jon "Bones" Jones, Rhonda Rousey and Anderson "Spider" Silva. Although Jones fought in UFC 182, that was after a several month injury lay-off, and most of a year since his most recent title defence. Rousey is losing her lustre because she already has run through all the credible competition UFC can round up for her, only one of whom managed to last a full round, and they've begun accepting applications from the Russian Women's penitentiary league. Silva, probably the MMA fighter mentioned most often as the 'greatest of all time,' was out for the whole of 2014 because he broke his tibia and fibula across the shin of Chris Weidman in a fight in December of 2013.
And the UFC is strapped for cash and 183 was to be Silva's come-back from a gruesome leg injury. The full numbers aren't yet tallied but early indications are it could have bested a million PPVs. And that's why the UFC let the fight go on.