I think those that say Burnett is in over his head is right, he approaches this like he's in a business venture with Jerry Jones, but he's not. He's going to get the same salary no matter how much or how little Jerry Jones makes.
I was in a job with a bunch of older colleagues who were rather upset that a guy in his early 20s would get hired and paid as much as they were. I had the same marketable skills and qualified for the job (I didn't know anybody in the company prior to my hiring, so I wasn't given the job) so they gave me the whole "you act so entitled bit" to which my response was:
"I worked my butt off to get where I am right now and in no way given my job. I was hired for this position, at this salary, because the company thinks that those same skills are worth that much. They know that if they don't pay me at least this much, somebody else will and will gain my skill set. You guys treat this job too much as the company giving you the money out of pure kindness. If you treated this relationship like it really is, a business relationship where the company pays you for a service, like you pay a carpet cleaner to clean your carpets than you might get somewhere. Basically, list up what you believe to be your marketable skills and qualifications and price them at what you believe them to be worth and then ask for that much. If this company won't give you the position and money you want, see if anyone else will. If nobody does, you were probably off in your estimation and need to rethink it."
So what does this have to do with the NFL players vs. owners? Basically if Burnett says that the supply of NFL caliber players was only so much and the demand for the players was so high, I don't see a way you could justify not spending this much on players' salaries, he'd have a point but instead, he went the 'but I might get injured and hurt! route' so it just sounds whiny and entitled.
FYI, the NFL spends roughly the same amount as other industries on personnel (59% of the gross income) so I think the owners are whining unnecessarily but if the players want to get somewhere, they need to face facts and stop trying to play the "it's our bodies on the line" card. Say you are the athletic elite and deserve elite salaries (and even that won't hold much water because so are olympic distance runners but they don't get squat compared to NFL players).