To me though, all you have to do is look at the proposals the owners have offered. So far, every offer they have made has gone way beyond just getting to a point that is fair for both sides. Now, none of the players offers have really gone as far as to achieve fairness for both sides, but, their proposals are far closer to the supposed "middle ground".
Personally, I think this is a bit of an illusion, based on the fact that the players offers have not been worse than the current system. So, the fact that they are actually giving ground from the current system looks like they are actually giving things up, while the owners are just taking things away.
However, I think if you look at it where the middle ground is a new system that guarantees the owners a profit, providing the league continues to bring in revenue at a similar level, while also maintains a salary structure for the players that keeps them as the highest paid professional sports league on average (by a pretty large margin), then I think you have both sides pretty much equally distant from that line.
Once they start working from that middleground, then I think they can get something done that is fair for both sides, and will be best for the sustainability and growth of the league going forward.
The problem right now is that the owners are working from that baseline (and of course lowballing, as any negotiator does at the beginning of negotiations), but the players are still using the old system as the baseline. So, even if they sit down at the table, and the owners start making conscessions, the players can't make the mental leap to realize that they actually are concessions, since, based on the old system (which is irrelevant in this negotiation), it is not actually a concession.
Furthermore, I think the agents and lawyers for the players know exactly what is going on. They have seen the numbers, but they also know that their only chance to get the owners above that middle line, is to dig in, and refuse to work from that middle line. So, they don't really explain this to the players, they just keep feeding the fire, and letting them dig in, knowing as agents (who have a lot longer shelf-life than players), they will benefit a lot more from even the slightest budge by the owners, than the players would.