Well... certain in-game missions imply quite strongly that cabs are actually cabs for people. In some GSO 'Catch Racer Tech' missions, the description states that the 'mission submitter's son has stolen one of their techs and that you must teach them a lesson by destroying it.' Another Venture mission of the same kind claims that the racer tech is driven by their 'champion' and in order to win you must destroy the champion. It even seems to make light of the fact that to win you must kill someone by being reticent in saying that that makes you the next champion...
Basically, i think there were meant to be people in them, which was why it was once possible to lose the game.
But they made it non-violent and removed that.
But they never followed through to the logical conclusion, by making the text and missions to match.
I think that when a cab is destroyed, that the guy inside is either teleported to another tech, or if there is no other techs, gets teleported to a far off space station where they are given a new tech.
Without thinking about it much, I had always believed a tech is an AI entity.
I (the player) am an artificial intelligence inhabiting the cab in question. I was dropped in the planet of TT by someone, or some corp, to harvest the materials there in competition with many others. I am dynamically upgrading and designing myself to complete the specific tasks at hand. When I switch techs, I'm merely switching "bodies", beaming my AI consciousness to the cab of the nearby tech. The "AI cab" blocks are simply conventional computers with simple instructions to perform while I am not inhabiting that tech. When I die, a saved copy of my AI is simply re-uploaded into either a new tech or one of my nearby techs.
As for enemies, both fellow AIs as well as remote controlled techs (perhaps from orbit) makes sense to me.
Just this, whats happens when the tech that you control is destroyed? You are not killed, so you are not human / biologic, a new tech is granted to you and you are transferred to the new one. I think that this that Saelem said matches this that is happening.
I do not like the idea of killing people at all, in special in this game, I am not sure why, would be due to the cartoonish environment.