Graphics is where the games and the designs for the new pokemon is where the games truly shined in my opinion. Two Gens later I STILL think that Hoenn was the most beautiful region we've ever seen.
I agree with you though, the fad ended. Pokemon was going to lose fans one way or the other, but the number increased due to the games.
I agree Gen 5 didn't really change much, but it did a really good job with what it had. At this point its my 2nd favorite gen (If were not counting remakes). I think GF did a really good job lol i'm still suprised I liked it as much as I did. IDK why, but I think they did a better job than Gen 3 did of leaving the old behind.