Why use a logarithmic scaling for an area chart? Given the data it's presenting, a logarithmic chart is completely inappropriate. If I take the rectangle of "HTC / Android" and add it to the rectangle of "HTC / Windows", what do I get?
If it was proportional you wouldn't be able to read the windows label in the first place. I like this setup. Works as well here as it does in disk manager, the first example I can think of commonly visiting with log scaled area.