Very true. Pretty much the whole series is driven by the characters and their reactions to each other and the situations they find themselves in. While this is true for many stories, it's especially true for Eva; the meat of the plot comes from the developing relationships between the pilots and those around them. The Angels just serve as the catalyst that eventually sends these kids to hell in a hand basket.
Come on now, the ending in episode 26 was rather cheerful. It was because the fans didn't like the happy ending that Gainax decided to give them what they wanted, a bitter ending.
