Spore made a huge impact, not only in mainstreaming the idea of an evolving game but in the ability to control characteristics and shape interactively and easily. Plus being able to share creations online was huge, even though so many of them ended up in certain shapes (humans being humans). Where I think Spore failed is in trying to rush through the first stages and get to the "civilization" parts. It would have better if it had a slower pace staying within the animal world. They also failed when they dumbed down and sanitizing the original game, which was much more violent (see the demo with Robin Williams)...but that's how nature is.

Thrive is very impressive, but it might be too realistic in its complexity and trying to include everything and that will keep it from getting popular. If I remember you can dial it back some, but it's still very technical compared to the simplicity that made Spore work. Maybe there can't be a good middle ground.