Way too much thought. Which is interesting, because apparently the bad camera angles and dialog that you were so focused on distracted you from what you wanted to know.
His parents died in the archaeological dig on Mars, and he didn't like how his sister worked there. He thought that the place sort of killed them intentionally. They have a conversation about this when they talk about what lines of work they went into. If I recall, in the semi-flashback when he's looking out the window you hear them asking for his help and him as a kid saying he couldn't do it, I think. Even if that wasn't enough of an indication as to what happened to their parents...Rock walks in and says, "This is where they died, isn't it?"
And no one could go into the ark gateway on Earth until the lockdown ended anyhow--assuming the transmission ever got there. I mean...they were on Mars.
As for the religious guy, I have met many a devout person who are in fact complete scumbags. It's what makes people so devout. I once knew a girl whose mother very faithfully went to church every Sunday, and went to confession all the time high on cocaine--to confess she was doing cocaine, and feel like she wasn't doing anything wrong. Hence why I don't like religious people, to be honest. Lots of devout folks are not actually the pious people they seem like.
I agree that the movie could have been a lot better, that it lacked a proper amount of action and combat, and that it strayed very far from Doom's story and that it was to the movie's detriment. But I wasn't sitting there with a notebook looking for complaints or anything--I knew all of that was butched from the start. That other stuff, though--"The camera didn't pan well during the first person sequence"--is just nitpicking, I think.
The thing that sucks is the original script for this movie that I read years and years ago, made a long time back, was identical to the real story with some minor 'enhancement'...but the whole movie was the Doom guy doing the doom stuff, and almost all the dialog was just him narrating what was happening. It was pretty good...I wish they'd have done that instead.
Was it decent from a mindless action movie point of view? Yeah, the fighting was great, can't deny that. Even if Rock having superhuman strength as he died was BS, at least the fight was decent.
Either way I think it was one of those movies nobody would have ever been completely happy with. If they elaborated on his parents people would have said there was too much plot, if they had more gunfights people would call it mindless, and if it was too close to the game people would've called it boring. So unfortunately it seemed like a lose-lose situation. This wasn't a normal videogame movie, this was Doom--we've been waiting for it for like 7 or 8 years now. Maybe more. They could've at least done us a favor and stayed SEMI-faithful to the story. But I see where both you two (S and Sonic) are coming from. My view of it rather then think of how bad it is, is think of how much worse it could've been. And from that point of view it doesn't seem so bad.
Though the Rock was trying WAY too hard whenever he hard to swear.