In other words - they can not fix it.

From the Everett Herald:

Boeing to indefinitely suspend 737 Max production in January
The Boeing Co. will indefinitely halt production of the grounded 737 Max in January, a move that will deepen the crisis engulfing the planemaker, complicate its eventual recovery and ripple through the U.S. economy.

Employees at the Renton factory where the Max is built will continue 737-related work or be temporarily reassigned to other programs, the company said in a news release Monday.

The 737 was a decent airplane. Their mistake was trying to graft a much larger engine on it and then to "fix it in the software". Not gonna happen...