Aerith learned from a young age that "words are wind". This is why she can see the kindness in Cloud through his actions and intent, not his words. She doesn't get put off by his facade/grumbling because Cloud's actions demonstrate his true character. #clerithpic.twitter.com/fBgInxRiue
Exactly, and examples are given too what kind of good actions she witnessed and Cloud’s ‘I’m coming for you’ surpass them all. You can literally imagine that nobody in her whole life did something so significant except her mother. This is why Cloud is so precious to her.