More people played (and hype and obsess) over FFVII for long periods of time. Frankly, for about 10-15 years, FFVII was the most popular console RPG and hence, that's why people make such a big deal about it being the biggest 'death' scene.
As another example, Last gen, KOTOR was one of the biggest games on the XBOX. As a result, the big 'turning point' of the story (which has a similar connection in a way to Aeris dying) is constantly referred to as one of the biggest plot 'surprises' ever. Is it really that revolutionary? Not really..its actually a common story theme in movies, books and even been used in other games. But because it was used in a popular game, it gained notoriety and fame.
Aeris dying had the same effect, but it has dragged on for much longer because the scene had little competition. When in all reality, there was many other games that had similar, if not more impacting scenes around it (heck, Suikoden did a year earlier). But FFVII was a much higher profile game and so people just remember that.
Six upcoming games you should look into:
