Wow. Are you serious? If so, you are totally clueless.
Give a developer the most powerful PC you can buy today and he can still make it crawl at 30 fps. He simply needs to add billions or trillions of polygons or particles, apply enormous textures, etc.
Like the previous comment says: it's a choice between better graphics quality or better gaming performance. Everything staying the same, more powerful hardware allows you to use better quality graphics for the same gaming performance.
Most people care. It's always preferable to have better hardware. Deal with it. Even if 3rd-party games may not take advantage of it, exclusives likely will.
dysonlu's comments