And probably because it's more "stable" in the sense that the bundled chromium won't change independent of the rest of the software. Plus storage is cheap and

And probably because it's more "stable" in the sense that the bundled chromium won't change independent of the rest of the software. Plus storage is cheap and plentiful, and while webkit is pretty close to chromium, it's not identical and then they would need to support 2 separate "platforms", even if only for that 2% of differences.