Firstly let me say I don't think the UFC is doing anything wrong.
Do I think fighters deserve more money? Yes.
Could the UFC pay fighters more money? Yes.
Now here's my reasoning why.
Just making it in the UFC is an amazing achieving. The UFC has approx say 400 fighters. If you remove all of the European, Asian, South American, Australian and Mexican fighters let say you get 325.
The US population is roughly 325 Million people. So just to have made it in to the UFC you are literally 1 in million(The top 0.0001% of the population)
Not only that but you literally need to dedicate your life and lifestyle around fighting to become the elite of the elite.
Personally, if any of us jackassess made it in to the UFC it would be the biggest achievements or our lives. Our equivalent of say making it in the olympic games.
Which brings to my next point. The thousands of athletes that are going to Rio Olympics dedicated their lives to their sports to represent themselves and their countries not for the fame or fortune. Pesonally, I believe if you want to sportsperson you shouldn't be doing it for the money because let's face it there are a lot more easier ways to make money.
Being a UFC fighter is a very tough gig, your career will be lucky to last 20 years and what you have to show for it after? Living in a caravan like UFC legend Ken Shamrock? financial problems like UFC legend Mark Coleman? A drug abused and wrecked body like Mark Kerr? No retirement/401k savings and massive tax debts?! Depression and an early death in your 40's and 50's? F*ck that!
Le'ts face the UFC is a business and their aim to make money and service debts. Zuffa has 400 fighters and who knows how many non fighter staff. They can't pay everyone millions of dollars, otherswise they will go broke.
Also, the fighters don't need to really fight for the UFC there are other organisations in the US, Europe, Japan, Russian, Australia etc. It's a market economy they can fight for whom they like.
Having said that revenue wise the UFC is doing fine. Let's say a PPV event featuring Connor or Ronda(plus others) sells 1million views and 30,000 tickets.
PPV Revenue $60 x 1,000,000 = $60,000,000
Ticket sales $200 x 30,000 = $6,000,000
Roughly $66 million revenue(not profit) for a popular UFC PPV, so UFC stop being so stingey and pay more money to your lower and middle tier fighters.