Boruto IS a brat. Sarada IS a naruto fan.
Just because Boruto learns not to be a brat because daddy is in trouble doesn't change who he is at his core, a stupid kid playing ninja, as Kakashi put so aptly.
Sarada has legitimate reason to view her father the way she does. He was never around, and she had much more logical emotional qualms about it, and was never a brat despite being in a far worse position than Boruto in every way possible. Instead, she is responsible, talented, and does not cheat for her fathers attention.
Sure Boruto has changed somewhat since then, but his past actions were not justified. At all. Sarada being a naruto fan is not a bad quality either, because he has admirable traits to him. She understands the importance and value of a Homage and what it means. Boruto does not care, and just wants attention, at the expense of the villages well being.
What killed me was during the ryogi arc (The ice people or whatever) he was upset with his dad for being the leader of a village that still had poor people suffering and workers so stressed they tried to commit bomb attacks- Yet he was trying to still take naruto's attention away from the village for himself.
Boruto had chance after chance to develop into a better, halfway decent character, but refused to until he got to fight alongside daddy and rescue him with Sasuke's help (Or rather, sasuke leading the charge and doing it all for him so he can land the finishing blow and feel special).
Boruto should have made this growth long before now. The problem with his character that will ALWAYS stick is that his entire start was a negative one, and many fans hate or hated him for the kind of person he was. The fans of the series should NOT relish the episodes where the MC gets publicly humiliated for being a liar and cheater and shitty friend. But that is what is happening, because Boruto has caused so many people to dislike him.
He is a "gifted genius" (Only cause he has 3 elements, only one of which can actually be used for real battle purposes) yet is weaker than both of his teammates, has THE PERFECT LIFE in every way but one, and wants to take away from the villages prosperity so that he can have literally the perfect life (Daddies attention), and he shows how ungrateful he is for his friends by almost refusing to go with them to the chunk exams, thus fucking them, until he is told he can get daddies attention that way, THEN he cheats one of his best friends out of a victory.
He is a horrible person in every way, no matter how the anime tried to make him this "Friendship guy beacon of hope" that naruto was. he isn't. He's a fraud. a liar. selfish. A cheater.
And i will not ever enjoy his character until he experiences more growth than "Daddies attention". He needs real pain and experience, and he needs to mature. He is STILL a brat, and has done nothing noteworthy to make up for ANY of his shitty actions. Hopefully Shikadai puts him in his place, and Sarada too.