Caramelmarmalade

 
Thats true. But before that there was more SS, like the wave arc, Sakura had called Naruto an orphan, and you had the forest moment where Sakura punched Naruto for trying to pee in front of the group while her inner self wouldn't mind if it was Sasuke. Then you have the Ino vs. Sakura which started over a boy and all that after. With Hinata vs. Neji and her sad background as well as the proud failure speech.
 
I don't think they see it as just eye contact. The poster mention how they like the first interaction because it more likable and they saw a possibility of more pro NH interactions. And when you see more of Hinata and her side story in part 1, I can see why one would cheer Hinata over Sakura. 
 
Like Nar123 and Bail O Lies said, the Sakura bias was established since the beginning, even though she was developing like Kishi first intended to. Seems like people weren't in favor of how Sakura was depicted at the beginning, especially towards Naruto, so when they saw that NH interaction, they begin to support it. 

I dont know what you guys think of hinata but i hated her from the very first time i saw her in the anime. That was me of 10 years old lmao.
My dislike towards her character is getting better, i guess, towards the series but ended up hating her even more with the reason you-know-very-well.
The whole discussions about SS never having sex together, makes me pity sakura even more. What? Sex with his clone? There you go girl. Deteoriating yourself TT.TT SP just ruined my fav heroine ever.