DARREN: In fact, it’s refreshing [that Lorelai doesn’t have an academic background]. It might even be to Rory’s benefit. Good things didn’t come to your family in one fell swoop, you struggled for it.
Darren is suggesting that Rory’s background might be enough to make her stand out from the crowd in the college application process, to make it seem as if she had to struggle for everything she’s attained (it’s really more that Lorelai has had to struggle for most of what Rory’s attained). Lorelai and Rory are carefully leaving Richard and Emily out of the narrative, and not mentioning the financial assistance Rory has had to attend Chilton (a good thing which came in one fell swoop).
You can see that this is the angle Darren himself is probably planning to use in his chat with a Harvard admissions officer – he’ll be putting in a good word for a girl from a middle-class single-parent family in a small town, with a mother who had become pregnant in high school, had to work hard to support them both, and doesn’t have an academic background. Again, the fact that Lorelai went to private school and is from a wealthy upper-middle class family where both parents attended Ivy League universities is not going to be mentioned!