At the beginning of March the league and the union couldn't come to an agreement on a new collective bargaining agreement causing the players to decertify as a union and the league to implement a lockout. Basically, those actions turned things to the courts.
Shortly following that, many of the NFL's 32 teams sent out an organized message to their fans and nearly every one included a message that it was the players, and not the owners, who walked away from the negotiating table.
The players, according to multiple sources, planned to meet with the owners March 28 and spend the week settling this mess. All that had to be done was have a short document go to federal judge Susan Nelson's court saying that the NFLPA's executive board would serve as advisors. The NFL's answer was no.
The NFL wants to collectively bargain and not recognize the union's decertification. The union isn't interested in that because it would potentially be evidence used against them that decertification was a scam. Instead of the two sides drafting documents that would allow them to continue to negotiate without the talks being used against each other in a court of law, they have decided not to talk.
If this is accurate, it's a frustrating move on the part of the owners. It seems that the best possible way to get a deal done is to simply sit down and talk. The two sides were reportedly making real progress during federal mediation and sit just (just?) a few hundred million dollars apart.
Instead of camping out at the federal mediation building in Washington D.C. as these two sides talk it out, we'll be waiting for a court ruling.