So, why blow up Megaton?
What reason could there be for it for the player character to blow up a settlement of people?
And no "cause of evil" or "cause of being a dike" or "cause of being greedy" comments.
I don't qualify them as good reasons.
Someone doesn't just blow up a settlement cause they're a dike.
And even if someone is "evil" they have to have a reason for actually wanting to blow it up.
If the player character was just a mass murdering psychopath he/she wouldn't have taken the time to wander around the place, find that suited dude, talk to him casually, plant a bomb then travel over the wasteland to his employeer to see it blown.
Nope, that kind of character would simply start killing people right off the bat, or (s)he would have killed them silently and try to torture them and possibly force procreation upon his/her victims before ending their lifes.
So... Why? What possibly reason could there be for any role one might take on in Fallout 3 to just blow up an entire settlement?