Because one gets tired of reading about Luciuses that rape assorted male characters (including his own son), Luciuses that are irredeemable bastards, and Luciuses that in no way resemble the chilly, snarky, idiosyncratic individual that make him such an amusing character to read in the first place.
Ginny was fairly certain that this wasn't exactly how she'd envisioned her rescue going, particularly when it came to the bit about being hefted over a shoulder like some sack of potatoes while her erstwhile savior's normally impeccable hair cracked against her nose with every step he took.
The identity of her rescuer in question was also something the girl felt a rather strong objection to. Really, Ginny felt that as rescuers went, she certainly could have done better than Lucius Malfoy, and she proceeded to make this sentiment known in the loudest tones she could manage.
"Idiot girl," Lucius ground out, and after a moment of briefly worrying if she really was fat now, Ginny realized that his breathlessness was due to a wound in his side and not because she was too heavy for him to carry. "Of course I had to save you. The Malfoy honour's at stake."
Ginny privately doubted the validity of Malfoy Honour, if such a thing did indeed exist, but she voiced no further retorts, and stewed over her mental evaluation of the situation instead.
Lucius apparently didn't feel anything was particularly wrong with carrying on conversation while fleeing for their lives, and so, after a moment of struggling through a thick patch of shrub, the wizard continued smoothly, as though they were simply drinking tea in some comfortably dainty parlor.
"If I don't bring you with me now," he explained reasonably, "My son will come back for you. And," Lucius added, sniffing grandly as he readjusted his grip on the small of her back (now realizing how inescapably bound to him she was, at least for the duration of this escape attempt, Ginny glumly regretted provoking the Death Eaters into smashing her kneecaps and rendering her unable to put as much of a healthy distance as she could manage between Point A, an increasingly effulgent Lucius Malfoy, and Point B, herself, an increasingly disturbed Ginny Weasley).
"Malfoy men have never made a habit of making fools of themselves over women, and that's not about to change now."
"Haven't you changed that already?" Ginny asked as tartly as she could manage, wincing as a surprisingly graceless leap over a hummock jostled her.
"I suppose," Lucius conceded, "But I'm counting on him to hate me so much that he'll wipe my name off the family tree and records, and I'll be forever doomed to be known simply as the crazy old bat everyone couldn't wait to go and throw off some bridge."