Kishimoto wanted to show how much Sasuke changed and was "lost in the darkness" and used Sakura to prove the point.
You know, his old teammate and the only girl who was popular enough to be shipped with Sasuke.
(Nobody cares about Karin aside from using her to make Sasuke stay away from Sakura or troll SasuSaku)
I'm certain SasuSaku fans hates as well Sasuke and Sakura in Kage Summit. Even Sakura's fans hated her be using as damsel in distress and the Fake confession in this arc.
But the vast of majority of SasuSaku popularity come from part 1.
So Sasuke's sorry and the Forehead Poke was enough to SasuSaku fans pardon Sasuke, just like was for Sakura.
Also Happy Pink Girl and Angry Emo Boy chemistry.
I don't care how popular sasusaku among the sasuke and female ships it's still a toxic and problematic relationship that should never have happened. He can show sasuke has changed without having him hook up with someone, heck he did that with fricking gaara.
I have seen plenty of sasusaku fans love that scene because he supposedly went truly dark at that moment, completely ignoring he did the same to karin earlier. Or they go on about how that was just sasuke doing "self-defence" because sakura was trying to kill him. If they had any self respect they should of said that while they may like it, but they should not be canon and just enjoy fanon instead.
The problem with the land of iron confession scene is that there was no follow up scene to adress what was she actually lying about and what was she being honest about. Which should be clearly not being fully over sasuke, but clearly falling for naruto.
I don't care how popular the ship was in part 1, part 2 they don't have the same relationship or interactions as they are a lot more negative to the point he tried to kill her. In fact by the end of part 1 he rejected her. Nor does the apology or forehead poke good enough to ignore all of baggage that ship has.
Also good girl Bay tropes sucks and they had no chemistry.