Do y'all really not get it?
SOTS portrays all the happy slaves/W-2 non-exempt associates/whatever and their delightful children as completely settled in and happy about the delightful life on the big plantation. THAT'S the objection. Remus takes his tongue-lashing from Ma with an almost subvocalized, "Yassum." The movie plays the tension over Remus overstepping his bounds and getting a hiding for all its worth: how far does he dare go in challenging the white-trash boys? Is he over the line for disobeying orders from the Big House not to tell the kid any more stories? Grandma gives him a kindly twinkle when he asks humbly if she's mad at him, and the movie breathes a small sigh of relief.
The cullud folk trudge home, tired from honest labor, a-singin' their hearts out, through the beautiful countryside of the Old South. That's their place. Sally has tofu for brains and the worst dress ever to appear on the Big Screen, and she runs the show, and that's HER place. At the end, rich boy, po' white girl, puppy, and the separate-but-equal boy from the shacks go off over the hill with Remus and Br'er Rabbit, and all's right with the world.
Crap.
As far as other movies being racist, GWTW was ABOUT the Civil War, for godsake. Comparing Song of the South to Gone with the Wind is like comparing Tobacco Road with Grapes of Wrath. One degrades with its stereotypes, one tries to tell the truth.