None of those things are conveyed in the games, except for Killzone 1 and Liberation. That's a serious problem for me at least. How can you engage people for a long period in a series without relateable characters or a sensible format for the story, COD notwithstanding. Killzone will get relegated to third and fourth place all the time if it just tries to be a doppleganger of another game but in space. The original Killzone sold well too even for all the problems it had, and people looked forward to the second because of the original. I really have no idea why they abandoned all the cool things that Killzone 1 offered and just added the technology of Killzone 2 on top.
To be fair, Halo has been doing this for years
In reality the vast majority of FPS gamers care mostly about the MP of those games, and for the KZ series that's little different.
I may be alone in my opinion but I rather enjoyed the story of KZ2. In that in KZ2 it wasn't really a story that was attempted to be told TO THE PLAYER. It was more of an event that the player experiences through the eyes on an avatar in the game world. You took on the experience of Sev; some random ISA soldier, and had to experience through his own eyes the ISA invasion of Helghan. It was awesome BECAUSE it didn't need to be anything more complex or developed than that. And the final assault on Visari's palace was like my favourite gaming moment of this gen BECAUSE of the fact that I felt as if it was actually meaningful, in that I had earned the right to fight in that most historic battle, by having fought my way through Helghan, tooth and nail to get there. It was gritty, it was immersive, and best of all the game barely took you out of the action for too long. You always felt as if you were in the fight, and its ultimate end result rested on your ability to suceed as a soldier.
I loved KZ2 way more than KZ1 BECAUSE of its immersiveness. Sure the art and atmosphere was there, but it was the visceral immersive war-like experience that made KZ2 for me. KZ3 was dissappointing in that regard, because regardless of what they did with the colour pallete, the game just felt like every other game in that I was watching a group of guys in a story being told TO ME, rather than THROUGH ME. It sucked, and pulled you out of the action far too much.
In some ways I can agree that KZ3 deviated too much from the dreary grittiness of KZ2. It just didn't feel like the same Helghan in KZ3, and the green petracite(?) stuff and super advanced tech of Stahl just seemed abit too clean and surgical for the KZ2 gritty space nazi design that made the Helghast in KZ2 so bloody indimidating. I mean the first time I saw the Helghast sniper in KZ2 i thought it was the greatest enemy design ever (still do for the genre). KZ3's elites just seemed a bit generic in comparison, and nowhere near as impactful or fear-inducing.
For me the changes to the KZ artsytle from KZ1&2 to KZ3 were a bit more than just the colour pallette. But anyway i'm glad that this game doesn't follow on from KZ3 and that they seem to have gone back to a more traditional KZ2-like Helghast design. I do hope they continue like that.
That said, I can see where Grall is coming from, and I don't think he's even being elitist or arrogant at all. I think he's probably just sick to death of hearing people whining about something they have only seen like 30 secs of, and I think that is justified. Sure, people might say that they are fearful for the direction of the KZ series based on KZ3, and I think that is also a justifiable position, but I would encourage those people holding out and waiting to see more of GG's vision for KZ:SF before making their minds up about what the game is and the overall direction it has taken.