Maybe we had a bit of miscommunication there but what I mean by interpolating the pixels is the same thing you are saying. Hinting alignes to the grid, plays with the stem weights... As far as I am aware, hinting changes which pixels the glyphs are rendered upon.
So, this is interpolating, interpolation means creating new data points by using known data; that is, changing the pixels it is rendered upon.
And while the roots of cells geometrically aligned, I don't think this means much in the end. It can be likened to holding many helium filled balloons in your hand. You can keep the strings in your hand pretty well organized, but how would the balloons look? I am aware that this is not a good analogy, but the relationship between the electronic grid and capsules in the screen aren't so dissimilar.
Not even the size of capsules are similar on epaper, here is another picture:
https://c2.staticflickr.com/4/3101/2...c1d423bf_m.jpg (I have no idea which ereader this is, but this is clearly epaper)