
I definitely don't think Olympus has Fallen hates America, is anything it's a love letter to Uncle Sam (saw it last night; corny as hell), and I'd imagine the new GI Joe movie will be as well. Haven't really seen anything about White House Down, and World War Z is based on a zombie book, isn't it? I see your point though, that's a lot of White House raiding for one summer/year! I guess they figure, hey Independence Day had a famous White House obliteration scene and was a huge success, let's pump out more of those kinds of movies! They're also capitalizing on recent tensions between us and other countries, but honestly I don't feel very threatened by the North Koreans that keep being the bad guys in these things. China would have been a much better enemy, which is probably why Hollywood is scared to piss them off.
It's just the Hollywood way with everything. Dark Batman worked? Make ALL our superheroes dark! People like the White House being under siege then a ragtag group or one man army retaliates and kicks a bunch of ass? Of course they do, make fourty!