Let me ask you this, what will shock you more:

- If your girlfriend (or a friend or family member for that matter) would be killed right in front of your eyes.

- All the civilians that die on a daily basis because of war/hunger/diseases.

Exactly. You have your answer right there.

The way it was done is shocking. Aeris dies and does NOT come back. She seemed to be the main love interest in the game and the primary party healer with no replacement. Sephiroth also destroyed an entire village in the same exact game, killing Cloud's mother and Tifa's father, yet it's not as big of a deal because we didn't spend any time with them. We just know that event helped shape Cloud and Tifa into the characters that they are, Aeris we got to know and love/hate. It's also FFVII.

Because FF7 has been played by 10m+ people.

And it is the most popular game in the series, by far.

It's not that Aeris' death is more shocking, it's that FFVII is more mainstream.

I personally believe Kefka's action greatly outweigh Sephiroth's but that's because I've actually played both games. Aeris' death was moving, but as you said, Kefka killed an entire nation because he was impatient.

And if you think it was just nameless face, read this and realize why that is such an incredibly emotional sequence.

What are you waiting for!?

Stop hanging around here and play FFVI Advance!

I always thought you were a huge RPG fan for some reason and you haven't played one of the best RPG's ever? o.O

This.

It was the first final fantasy for a lot and it was unexpected and shocking to lose a main character. Not a single main character has been lost in any final fantasy game since.

That's pretty much an answer to your question, tehsage. That is absolutely correct.

Palom and Porum were terribly annoying, and mostly useless, too.

I find it more shocking that people think Aeris is the first heroine/female protagonist/main characters interest/whatever that dies through the course of game in JRPG.
I haven't read/heard that for some time though. Fortunately.

THe thing with Sephiroth burning the village, it just didn't seem to matter.  The act of burning the village was overshadowed by other things and you just didn't think about that, you were thinking about Sephiroth what the fuck he was up to and what was Cloud's past.  You were just so disconnected from it.

With Kefka and Doma, it was purely focused on Kefka and his horrible act.  Later, you directly experienced the aftermath of that act and it was just an incredibly moving piece. Everything you did, Cyan in Doma, the camp, and the phantom train, was all because of what Kefka did.

Watch my above link if you don't believe me.