you're probably right, but have a look at our own riot controles.
They have tanks and armored vehicles too, why? idk.
And you forget they also managed to bring tons of guns to the arc as well, so...^^
As I said I generally agree with you, still one or the other controllable vehicle would simply add some variation to the story based side of the game.
It depends on 'how' controllable it is. I've seen games with vehicles that had a fixed path, but you could still use some kind of weapon (like an MG) However, while manning the weapon, you were an easy victim because you were partially exposed and not mobile at all.
You're right about the weapons, but take in consideration that weapons are easy to carry around (when they fled from the mainland) and are less resource heavy.
As for riot controls: You probably live in a country with millions of people, that's like 100 - 500 times as much people as there are on the ark in total (50.000) Let alone the original population of 5000.
Not too sure about this. When I spend £45-50 on a game I want more, not less. Imho these days to compete with the top contenders such as halo, BFBC 2 ect you need to have vehicles. If this game is to be great (i.e. memorable) it needs to stick to the times, And not take a step backwards. which is what splash damage are doing by NOT including the use of vehicles.
You get body types, extreme customization for an fps, a fast paced objective based game with the ability to play the singleplayer as multiplayer, with 8 person co-op, the smart system and you still want more? They compete by being original, adding new things to an FPS, not by copying the mainstream games.