As I said, it would be great character development for other characters. Twilight or Rarity might learn that they shouldn't take people for granted and such things.
What? Are you seriously saying that writing Spike out is a bad idea since Fluttershy won't get any character development?
Heeeey! Remember Derpy Hooves? Remember when they tried to write HER outta the show? How did THAT turn out? Yeah, Spike is not going anywhere...
That was in the past, I think that this fandom have matured enough since than that we can act as adults when they remove a character.
[video=youtube;Sg-wtsocxHY]https://www.youtube.com/watch?v=Sg-wtsocxHY[/video] This fandom is as stubborn and sensitive as it was back then.