Funny you should mention that as it only got silly (comedic style) after Resident Evil 3. However at least the reason why the outbreak occurred in Raccoon city plausible (for computer game story telling stand point I mean.
But also Umbrella used the outbreak to do some field testing (with the UBCS mercenaries), so yes still silly but hey, making the best of a bad situation!
In a way I like the Umbrella from the movies better because they are so completely and singlemindedly evil it reminds one a bit of Doctor Evil. In the latest (awful) installment civilization has fallen and the world is overrun with the T virus so what is Umbrella doing? Making bioweapons! Why? For sale apparently. Who exactly is supposed to buy them is another question - it comes off more like Umbrella just sits in their underground fortress and ponders what sort of evil they can do each morning when they get up. It's so extreme it's funny.