I'm almost sure that this kind of recommendations comes from Rookgaard and Isle of Destiny but I was thinking that they only recommend Venore to paladins. If I'm not bad they used to recommend Ankrahmun for premium mages.
Yet, the reason is quite easy, Venore before 9.1 was the most diverse and safe FACC city, Now is just the most diverse city which let you kill mobs for almost every lvl. Now even provide 2 hunting spots that make it better (Coryms and Stonerefiner). The others FACC cities have nothing comparable to the old or the new Venore. For PACC ofc there are other cities but again I though mages/knights were encouraged to those cities such as Ank, Edron, Port Hope.