The combat world of MMA is unlike any other sport on earth. Although those who participate are categorically sporting athletes, we use the term 'fighters' to describe their profession, but at the moment, much of the 'fighting' is taking place outside the cage.
Unlike most sporting industries, like in football, basketball, the NFL etc, figures that compete in fighting organisations such as the UFC are doing so purely as individual contractors. From a monetary perspective, they only make a living wage when they step inside the ring, and any support/training they receive will be paid for out of their own back pocket.
In a nutshell, times can be tough for those climbing the ladder in this industry. Despite the UFC being visualised as the promise land for fighters, the organisation has a distasteful reputation for their underpaying of those at the bottom of cards.
It's always been a publicly discussed issue by both competitors and fans, but now financial concerns are being voiced from even the top names in the sport.