The purchase has been a fiasco. It was sold for at least double it's worth. WME will have a long long road ahead to ever make a penny and you're not wrong, that's a bad for business.
Basically the UFC made itself too big for it's own good. It's model (cards every week or so) does not appear to be sustainable. They don't have enough time to hype up more than a couple cards a year, leaving the majority of the cards lacking the "must see" element that built the PPV model to begin with. Bonus - Half the time they have a huge card, at least one guy pulls out and they don't appear to have a solid backup plan.... despite obviously needing one at the most critical moment.
Then they shot themselves in the foot with the Mayweather vs Conor money grab. They essentially allowed they're biggest current star to become independent of them. They need him for than he needs them, and that's bad. He literally doesn't need to fight ever again, so we get the cluster fuck that has been 145 and 155 for literally two years.
Plus the purchase came at a time when USADA was getting into the mix, so we end up with lots of big names getting popped and suspended. They lost a lot of time and PPV caliber fights just between Lesnar and Jones, and then you gotta toss in guys like Machida, JDS, Romero, and Mendes.
And they keep doing moves that show they don't understand what to do other than make money-grab -fights. GSP coming back? Great? Fighting a champion above his class, taking the belt and dropping the belt? Not great. Getting Cyborg? Great? But having literally three possible women to face here in an entire division? Not great. Lesnar returns to the cage? Great. Shows up in a scripted interview, that has him apparently as the #1 contender despite having a losing record over the past few fights? Not great.
They're fucked and it shows.
Sadly if the Fertitta's had just sold it for less, the new owners wouldn't be in this position. Ironically the two guys that built the UFC from the ground up, into a billion dollar industry, may have signed the UFC into eventual bankruptcy.