The point is people liked Aeris a lot more, and that many players viewed her as a potential love interest for Cloud probably made it all the more impacting. She doesn't die after a boss fight, doesn't attack and get stopped, she's kneeling down one second and in the next she's been ninja'd in the back. You had the fancy cutscene which Squaresoft was good at back then, and then her theme plays while you fight Jenova. It was much more shocking. And probably even more so because FF7 was the first Final Fantasy many people played (for some even first jrpg) and they weren't used to such plot developments.
I don't think Sephiroth would have been as popular if he hadn't killed Aeris.
I can't save him. But if I can save some of you, I'm going to do it.
I liked both Galuf and Tellah, especially when they fight their games respective bosses. Seeing Galuf and Tellah stand toe to toe with Golbez and Exdeath was quite enjoyable. Galuf wanted to protect Bartz and the others, as well as defeat Exdeath, while Tellah flies into a rage against Golbez.
The thing about them is they didn't sit around and wait to die. Unlike Aerith who spent her last moments on her knees, doing nothing. Galuf and Tellah took the fight directly to the enemy. maybe people would remember them if they had died doing nothing.
Strider is something of a god of equine necro-brutality. -Master ZED