One thing about Salt's comment on the Afrikaners is to remember when this book was published. It was presumably written a year, or maybe more, before then, at a time when apartheid in South Africa was only painfully slowly coming to an end. There was fear of a civil war in South Africa and the storming of the Kempton Park World Trade Centre by AVF and AWB had yet to come in 1993, a point which was seen as coming close to provoking a war.
Thus, I would argue, especially writing in the late 1980s/early 1990s, the portrayal of the time-travelling racialist/racist fanatics, was pretty accurate in terms of how you could see such men behaving and talking, nightly on TV. They may now seem 'puppy kickers', but at the time the book was produced this was an accurate reflection of what you could witness and, in fact, can still see. Nick Broomfield's two documentaries of him meeting Eugene Terreblanche, in 1991 and 2006, do highlight this, as does Louis Theroux's 2000 interview with him.
The quick abolition of slavery by the South in the novel does jar. However, it is perhaps not as much of a stretch of the imagination as again it might seem now. Teaching of the American Civil War used to highlight a whole range of aspects which are now neglected in favour of an exclusive focus on slavery. This neglects, for example, that some slave states fought for the Union and there were many thousands of supporters of slavery who lived in the North; indeed fought on the Union side. Given that Russia abolished serfdom in 1861, it might not seem as extreme as it might now, to envisage that one way or another the South would have been compelled to scrap formal slavery. What is likely, though, as was the case in northern states which were early abolishers of slavery (of course, all states had had it when the USA was formed), such as Ohio, instead used indentured labour which was slavery in all but name. Turtledove, thus, is getting to grips with a more complex picture than the common view of the war these days.
Despite Salt's comments, I think this book actually is a challenge to the Confederate apologism something which Turtledove was acutely aware of. His attitude to the issues is clear in terms of his sustained public comments through the years. The book shows that, even with assault rifles; even with racist support from the future, the Confederacy could not sustain its policies and would have been compelled one way or another to alter, just as the autocratic Russian Empire had been compelled to do. That is not an apology for Confederate behaviour; that is a dismissal of Confederate fantasies which too many other AH books pander to without challenging.
I think when critiquing we need to be careful not to have a triggered response to the superficial and actually dig into what the author intends. Of course, they may not achieve their intentions. However, the simplification of analysis of the American Civil War, ironically, has not helped a genuine analysis of American history and why the issues of 170 years ago remain so alive for the USA today.
My final point is: what is wrong with parallelism? I will continue to argue that it is in fact a necessity for any AH author that wants to have a chance of selling books in the mainstream; beyond an actually small circle of specific readers.