I gave up somewhere after Nick died but before Madison died.
There seems to be some behind the scenes turmoil over Kim Dickens departure similar to that of Laurie Holden over on WD. Laurie was told she would be there for at least the first seven seasons then dropped without explanation. My guess is something like that happened with Dickens and she was not happy. If you watched her departure episode Madison hardly appears while Alicia and strand give the exposition and Dickens face and demeanor on the Talking Dead says more than her words. I suppose there is a chance she could still show up alive given the oblique ending but really a long shot. I think Lincoln leaving the show has to do with money like Lauren Cohan along with family time.