aerith had always wanted to live. she yearned to see the future and live with her friends more than anyone, tifa says it best. 

aerith may have found eventual peace in her passing, but it was most certainly not a happy ending for her. its not what she wanted. she was so full of life and love for those around her. despite all her circumstances she still wanted to live and protect those around her. she wanted to explore and see new things, and live the life she'd always wanted to live.