I've seen this argued too, but I think it sort of really underestimates what real relationships are like. As if only completely positive interactions can help a relationship grow. The confession, to me, ended up being fairly neutral towards NS. Some really good things happened, like Sakura revealing how proud she is of Naruto and the removal of the POAL that burdened him. Sakura was taking steps to grow as a person and made it clear how highly she thought of Naruto.
It was by no means a perfect confession however, in that she mixed in obvious lies and had her own secret agenda that wasn't truly about revealing any of her feelings (even though it was meant for Naruto's own good). She mixed her 'I love you's with 'how could I love a criminal anyways', which is just...not a good way to go about it. It made her seem like she was settling just because Sasuke was a bad guy. It wasn't until she had already lost Naruto's belief in her words that she hugged him and told him her true feelings. Because of this, Naruto probably still doesn't have a good idea of how she feels about him.
One thing I liked about the anime adaption was that when she hugged him, it seemed like that was the moment she really thought about how much Naruto meant to her. It gave the impression that right then she could have truly realized her feelings for him and thus she was so hurt moments later when he told her he hated people who lied to themselves.
I'm still guessing that Kishi doesn't want to conclude the love triangle till close to the end when Sasuke/Naruto's issues will also be concluded. I don't believe the pairing was reset in that it is still growing and evolving as the story progresses unlike NH which doesn't have progression on Naruto's end and SS which doesn't have progression on Sasuke's. NS is the only pairing that progresses on both ends.