On topic of aspect ratio, not sure how much of this is said already, but many games let user himself choose how he wants to scale the UI. Most 3D games support this now. For example imagine someone with imaginary 2400x1800 resolution. You can't know how big or small he wants the UI to look. Maybe he is used to look small things possibly because his display is huge. So just because resolution is big, it's not *always* the right choice to scale things up. Depends on what you're drawing...

Also as i mentioned OpenGL earlier, even if it's 2D game its all vector graphics (polygons). Texture size doesn't matter (well, low/med/high settings for performance can be good always), bi-linear filtering is smooth to look at. They can also be drawn pixel-perfect without scaling. Vector graphics have speed benefit where you don't have or need your own doublebuffer, to get effect of "stretching" graphics.