Why do people complain about Ultramarines being featured? Everyone knows and acknowledges that they're GW's poster boys, yet they act appalled when they're used instead of another chapter. It's like if people complained that in Lego video games, you don't play as a Technic or Belleville figure instead of a minifig.
Relic has the totally hard core Blood Ravens, so why did they not go with them? Ultramarines have a dumb name, and a dumb color, plus their omega symbol is upside-down for extra fail.
My Dark Heresy/Rogue Trader/Death Watch rpg group likes to look at all the retcons and such as the Ultramarines manipulating official propaganda in a bid for power within the Imperium, with them pushing a hide-bound, rules-focused codex on everyone else while violating its principles in spirit with everything they do (they violate the 1000 marines per chapter in spirit, since their successor chapters are so closely tied to them that they are effectively still a legion, or rather more than a legion at this point; they violate the separation of powers by having their own guard units and navy; they fobbed off a jumped-up guardsman as a primarch, and attributed some of the deeds of other chapters' heroes to their own people).
The Blood Ravens, on the other hand, have much better colors, a much more interesting and mysterious chapter history, and are available for Relic to do pretty much whatever they want with it. Why they didn't use them for Space Marine I can only guess (probably something to do with SM being the GW flagship product to introduce the setting to console gamers, so they insisted on using their posterboys for it).