The History Channel is running this 2 hour show on "April, 1865" from the book of the same title. The author's theme is that the United States is the --only-- nation throughout history to ever go through a revolution and come out stronger than before. And it was Grant and Sherman who were the main agent's of dead Lincoln's policy of "malice towards none, and charity for all," that made it possible.
Robert E. Lee is also quoted as saying that he surrendered as much to Lincoln's good as he did to Grant's army.
Those that attack President Lincoln's memory either hate the United States and what it stands for or they don't know the history.
Walt
I suspect it's both.