Heh, I bet someone will inevitably make an AMV of that on YouTube.
Considering Brock was Peter's "oldest friend", he sure forgot quickly that Peter lost his parents, had his uncle murdered, and the Parkers struggle for money. No, none of that matters nearly as much as Brock losing his job. But some people are like that. Tragedy can bring out the best and worst in people, and for Brock it brings out the worst.
I mean, while Brock certainly isn't as bad, even Hitler played the victim card. No one believes they are as bad as they are. It is always someone else's fault. Brock was allowing his hardships to twist him into a creep before the alien.
MJ: "Pete may not be perfect, but whatever his faults, he's twice the man you'll ever be."