@Dobromir, agreed.
It just goes to show the popularity of Nico. People like shipping her. Tsundere is like blue jeans - it goes with everything.
Plus she's kind of a classic underdog - the hard worker with a chip on her shoulder because she doesn't have special talent like some around her. She doesn't get respected enough, so she overcompensates with attitude, pretense, and jaded grit. She can seem selfish and full of herself, but in reality she's a responsible and reliable child of hardship who is devoted to her family, knows the importance of success, and determined to not let life walk all over her. People root for that.
I also think Honoka is criminally under-shipped. She's the cutest, pluckiest, most irresistable protagonist ever foisted on an ensemble cast and deserves more attention.