In a limited internet search, I found several sources that all reveal MCD employee turnover in 2008 was reported as 44%. I also found that over half of their workers are part-time employees and a large percentage of those part-timers were college and high school students.
So from the CEO's perspective there is a far greater supply of people looking for minimum wage versus the limited number of jobs available at MCD. The jobs are not skilled labor, they literally need a warm body and that's about it. So what is the CEO's incentive to raise the wages? If there were a ton of unskilled labor jobs available which decreased the supply of unskilled laborers below the demand MCD has for unskilled labor, then you will see the wages increase. So Nancy Salgado's options are: 1) continue to work for minimum wage; 2) look for a higher paying unskilled labor job; 3) develop skills to satisfy demand for skilled labor positions; 4) get an education to satisfy demand for professional positions; 5) become an entrepreneur and start her own business where she can determine her own salary. As heartless as it sounds, the truth is that Nancy Salgado's skill set is not the CEO's problem.
With that being said I didn't see the video. I quickly glanced and saw he made some sort of remark that he had worked for MCD for 40 years. It was an emotional, heat of the moment response. Not very professional if that was his response. But in a nutshell what is he supposed to say? About the only honest answer is: you are in an unskilled labor position and minimum wage is the going rate for unskilled labor.