You're making it too simple. Cecil wasn't cold in the beggining, he was a villain. And he had regrets for attacking Mysidia. Squall was merely a dumbass.

Kain wasn't bad, he was being controlled by Golbez. And he wasn't Cecil's rival, they were like best friends.

Anyway, I'll point a difference.

Cecil/Kain/Rosa - Great.

Squall/Rinoa/Seifer - Ridiculous.

See? There's a HUGE diference, after all.