it's all relative
Like a lot of other responses, there is a large majority of crew that is simply retired guys looking for something to do - the "I don't really need the money" guys who just want to mow rough in exchange for free golf. And unless you're in a market where you have a 12-month golf season, golf course work is a seasonal job anyway, so you really shouldn't be depending on this kind of income to support yourself and/or your family. For the college kids it should just be gas and party money. If you HAVE to by the $600 iPhone with the $100/month unlimited data plan and drive a new Dodge Ram 1500 - maybe you should be doing something else besides taking a job on my crew at $9/hour and bugging me for a raise every day.
On the other hand, the Assistant Superintendent who may have a young family and is trying to make a career out of it - they can be labeled 'working poor' if they are only paid a salary in the low $20's and are expected to 'pay their dues' by working 60 hrs a week with no overtime and no time to get a 2nd job to help make ends meet. If there is a 'working poor' problem in the industry, i think this is it.