In the West, Tales of Vesperia was released on the Xbox 360. Only. In Japan, it was released on the Xbox 360, forcing Japanese people to buy Microsoft's console. Then, a year later, it was released on the PS3.
Suspension of disbelief is apparently no concern for the typical Tales of Vesperia player, as seeing Klonoa, Mr. Driller or KOS-MOS in the Namco Bandai RPG won't be a distraction. It certainly won't get in the way of selling downloadable content.