At the start of The Muppet Movie, Kermit the Frog plays the banjo and sings a cool song called "The Rainbow Connection," a call to all the "lovers and dreamers" of the world. In the movie, Kermit and his friends set out to pursue their passion of making it as entertainers in Hollywood.
John Galt is kind of like Kermit the Frog. Really. Like Kermit, Galt unites his friends and his chosen family on a quest to pursue a passion: for life, happiness, work, values, a soul mate...basically, all kinds of love are united here. There is no break between different kinds of love in this book, whether it's romantic love, brotherly love, love of work, or love of certain ideals. All kinds of love are united by a common set of values, which Galt outlines in his radio address. By bringing together all these different kinds of love, the Atlantis crowd is living in a sort of harmony.
The point is that in the world of Atlas Shrugged, love is a really positive, all-encompassing thing that doesn't allow things like jealousy to screw it up (see, for example, Dagny's love quadrangle). On the flip side, we see a lot of examples of love being destructive and harmful among the looters of the world. Lacking Galt's values, these people speak of "brotherly love," sacrifice, and pity but end up causing destruction and harm.
Dagny's love of her railroad is ultimately damaging, since it leads her to stay and suffer too long in the "outside" world.
Self-love and high self-esteem play a hugely important role in romantic love here.