Why do we have to have flashy 3D graphics?

[Smidlee]

Remember the reasons why the Metroid Prime went 3D when the GC first came out?
1) it was cheaper to develop than a 2D Metroid
2) Since 3D art takes less man hours than 2D, Nintendo could develop 3D metroid faster and easier than a 2D one. Thus quickly increasing GC AAA titles.