There are a ton of former Warhammer Online developers who haven't made it into the game's final credits. And they are not happy. And understandably so! That's months, sometimes years of work, going totally unrecognised. Well, the IGDA (International Game Developers Association) are on the case, calling the snub "disrespectful" and using it as the latest example as to why the industry should adopt their idea for a set of universal crediting guidelines. IGDA's MacLean: Missing Warhammer Credits 'Disrespectful' [Gamasutra]
@Sushmonster: Yeah, hey, why credit anyone for anything? I mean, if the credits are so irrelevant, we shouldn't even bother listing them in the first place, right?
As for why they feel they deserve it if they left or were fired: if their contributions are still in the game, it's irrelevant. The credits aren't a list of "Who works for the company now". They're a list of who contributed to the creation of the game. By excluding someone from the credits, you are, in essence, denying their contribution and attributing what they did to other people.