Have you ever felt like Martin doesn't like Cersei? The way he writes about her made me question? I mean she is both evil and stupid and it seems like we are supposed to laugh at her.
Cersei is pretty evil, and while I don't believe she's stupid, it's hard not to laugh (incredulously or otherwise) at her many, many bad ideas over the course of the series. Especially in AFFC.
But it's also clear to me that GRRM has compassion for this villain he's created - and that he has right from the start.
Let's put this under a cut for domestic violence and sheer length.
Ned touched her cheek gently. "Has he done this before?" "Once or twice." She shied away from his hand. "Never on the face before. Jaime would have killed him, even if it meant his own life." Cersei looked at him defiantly. "My brother is worth a hundred of your friend." Eddard XII, AGoT
GRRM chooses to frame the pivotal confrontation between Ned and Cersei with the reality of the domestic violence Cersei has experienced. Whatever else happens in that scene, whatever else she's done that might or might not be justified, the author makes sure the reader knows, Ned knows, that Cersei has good reason to hate Robert.
When she hesitated, then sat, Tyrion knew she was lost, despite her loud declaration of, "I will not marry again!" "You will marry and you will breed. Every child you birth makes Stannis more a liar." Their father's eyes seemed to pin her to her chair. Tyrion III, ASoS
This is re-emphasised as Tyrion witnesses Tywin's abuse of Cersei. Even Tyrion, who also has good reason to hate Cersei, cannot help but see how their father completely ignores Cersei's desires, reduces her autonomy to rubble, and above all makes her feel small. This is quite deliberately in Tyrion's PoV to make that dissonance stronger. Cersei is awful, but Tyrion can take no satisfaction in Tywin mistreating her.
Similarly,
His sister sat in a puddle of wine, cradling her son's body. Her gown was torn and stained, her face white as chalk. A thin black dog crept up beside her, sniffing at Joffrey's corpse. "The boy is gone, Cersei," Lord Tywin said. He put his gloved hand on his daughter's shoulder as one of his guardsmen shooed away the dog. "Unhand him now. Let him go." She did not hear. It took two Kingsguard to pry loose her fingers, so the body of King Joffrey Baratheon could slide limp and lifeless to the floor. Tyrion VIII, ASoS
Cersei's grief over watching her son murdered in front of her is a key character moment for her. Is Joffrey a good person? No. Is Cersei's immediate response of demanding Tyrion's arrest a good and just idea? No. Is that grief still real? Absolutely.
It was more than Cersei could stand. I cannot let them see me cry, she thought, when she felt the tears welling in her eyes. She walked past Ser Meryn Trant and out into the back passage. Alone beneath a tallow candle, she allowed herself a shuddering sob, then another. A woman may weep, but not a queen. Cersei III, AFFC
That lasts. It's not healthy but it is genuine. The author isn't putting this in here so we laugh at her. The author is putting this here to help us remember throughout the parade of evil and stupid crap Cersei's about to do that Cersei is a human with human emotions.
And when all that crap has backfired on Cersei, the author makes sure we know that the punishment inflicted on her is not for her sins but instead for her biological sex. He shows her break from that treatment.
Words are wind, she thought, words cannot hurt me. I am beautiful, the most beautiful woman in all Westeros, Jaime says so, Jaime would never lie to me. Even Robert, Robert never loved me, but he saw that I was beautiful, he wanted me. She did not feel beautiful, though. She felt old, used, filthy, ugly. Cersei II, ADWD
The walk of shame is just misogyny, pure and simple, nothing to do with what Cersei's actually done wrong. It is deliberately not karma out to get Cersei. It is deliberately not comeuppance. It is a reminder that Cersei has a point all those times when she points out she's been treated differently because of her sex - even if it's not the whole of the reason people don't respect her.
Even if a reader doesn't think Cersei deserves mercy, even if a reader finds her political bumbling funny, there's a lot around her that shows us that the author wants us to think carefully about what made Cersei both a horrible person and a horrible politician. She is most definitely not there just to be the butt of the author's joke. That's Victarion.