Odious characters in Trollope and how Trollope squanders his resources

Who's more memorable - Iago or Othello? Shylock or Bassanio? We like the bad guys, the oddballs, the weirdos - at least we remember them. That's the main problem w/ Trollope's Barchester Towers: he creates a slew of truly odious characters, each distinct, each much more than cardboard villains because we can also sympathize with them and pity them (to a degree): the Bishop's officious wife, the narcissistic Signora, the self-centered Bertie Stanhope, and most of all the conniving and self-righteous Mr. Slope - but the problem is that, by the end of this long novel, the bad guys are pushed to the margin as the story focuses on the romance between Mrs. Bold and the (shy) Mr. Arabin - tied in with the (financial) salvation of the timid but morally upright Mr. Harding - in other words, this is a typical British novel of its time, with all of the (major) characters brought back into good graces and into the fold of society. But we don't care - and neither does Trollope, as he half-admits in one of his really cool narrative asides in which he apologizes for compressing into a day or two the courtship between Arabin and Eleanor Bold rather than drawing it out of months (and chapters). What held us through the novel wasn't Eleanor's plight but the personalities of the wicked, the eccentric, the hypocrites, the frauds (Dickens-like characters, but more rounded and complete). Now I have to say that, first, I have a chapter or two still to go so maybe T will bring some of them, or at least Slope, back on to the stage and, second, this is a six-part series - so maybe we hear from Slope again in a later volume (not in volume 3, however, which I read out of sequence). Too bad, for all his words, Trollope can tend to squander his resources.