Thirded, but...
It's a mistake to think Aerith is some kind of Jesus figure, a necessary sacrifice to save the Planet. When the Lifestream came forth to drive off Meteor, it was the Planet who did that, not Aerith-in-the-Lifestream. As I understand it. Holy didn't require a blood-offering in order to activate. I'm not even entirely sure whether Holy worked at all. At the end of the day, the Planet saved itself. Cloud & Co took out Sephiroth, which ended the force of his will pulling Meteor towards the Planet, and Shinra Inc made it possible for them to do that by breaking the seal over the Crater.
Aerith didn't need to die. As I understand it, that's the whole point and message of her death. Death is random and cruel and pointless, and snatches people away from us right in the midst of life, leaving us to figure out a way to carry on without them. Given that this is the message her death is intended to convey, I find it interesting that fans have worked so hard to re-work the significance of her death so that it becomes the exact opposite of what it was intended to be.
Having a way to resuscitate her would completely negate the impact of her death. In real life, we can't bring the ones we loved back to life, no matter how much we yearn for it.