3. I'm gonna get flamed for this but the problem is illegal labor
I started working in restaurants in my early teens. As soon as I figured out I could make more money with less hours than my paper route I switched.
Over a decade later I went to, what was then, the most accredited culinary school in the world and graduated with a B+ average. (Culinary Institute of America, Hyde Park NY graduated 2/1/91)
I spent over 25 years in that industry and I can tell you without any hesitation that the reason pay is so low is that illegal workers are willing to do the work with no regard for labor laws. They don't expect to be paid overtime and most don't even worry about minimum wage. They prefer to be paid under the table so they don't pay any taxes. They also don't care about the time off they are legally entitled to between shifts or the breaks they should receive during work. They don't even make workers compensation claims when/if they are injured. Legal laborers simply can't compete.
I now work for a friend who started his own landscaping business and the problem there is similar. We don't use any illegal labor but many of our competitors do. It is pretty easy to see what is going on when someone has us bid for a job, which we would put a 3 man crew on, and then we see another company there with 6 or 8 men on the job. It simply isn't possible to be above break even on these jobs if those workers were being paid what the law demands they should be paid.
I don't blame the individuals for this. I know they are just trying to make a better life for themselves and even being exploited here is better than the life they had elsewhere. It is still a problem for people who are trying to make a living legally and the numbers in that article illustrate the problem fairly well.
Exploitation is the problem and it needs to be dealt with or this will just continue to get worse.