Let's get one thing cleared up (only ONE since I'm not much of a debater).
Cloud may or may not haved loved Aeris. Square is pretty much refusing to tell us who he DOES love for fear of upset fans not buying their games.
However, him grieving over Aeris' death was not necessarily love. I mean, if a close friend of yours died, would you just shrug and go, "Oh well, I can always make a new one", or would you be overcome with grief and guilt?
Besides, I'm pretty sure it would have been worse if Tifa died. He's known her for longer and it would have been worse for him.