They're not random accusations. Some of those guys are a bit too fanboyish, but I believe it is undertracked somewhat. I've been monitoring weekly sales since VGC took that functionality away and here are some observations.
1. NPD had God of War III sales in the USA at 1.1 million in March. VGC have is at 950k. Thats 150k undertracked there itself
2. God of War III's Platinum release in Europe had zero effect on sales.
3. God of War III's Greatest Hits release had no noticeable boost on American sales
4. God of War III was at $15 last black friday at gamestop, k-mart and amazon.com . There was no boost. The Gamestop deal ran till the 27th of November. A whole month @$15 during the holiday season which had absolutely no effect on sales.
5. At times, God of War III had eerie negative sales of around the 5-9k range in Others and America after the redesign in 2012 in the weeks of 21st and 7th January, there was something clearly broken about the Vgchartz sales algorithm. The game had its "normal" sales back in the weeks between.
On the bright side though, God of War III did make a return in the USA charts at the 50+ postions since Ascension was announced.
We don't have any idea about the shipment numbers either so its tough to know whats really going on, but based on what I've observed I'd say theres a pretty good chance GOW III is somewhat under-tracked.