RE3 had a plot? Even by RE storytelling standards (which is rock bottom low), I don't see how 'Jill escapes from the zombies' constitutes a beginning, middle or end. The other RE games had at least one of those.
I'll concede that the dodge is neat, but unless you're facing Nemesis, it's not really needed.
You're not the most attentive if all you got from BH3, even without reading up on its background plot, was "Jill escapes from the zombies". Particularly since the game contains the most defining point of the series storyline (Raccoon City's destruction) and elaborates on plot points found in BH2 as well as introducing new ones, namely the involvement of the U.S. government, the rivalry between Umbrella's different branches and each of their reactions to the incident. By comparison, BH2 is pretty tame.
Everyone would do well to read this interview.