You make a good point, and it isn't as simple as I put it. The implementation makes touchscreen-based scrolling (especially with finger) more unusable.

When I use Fennec or MicroB to browse Slashdot this is already a problem. In the middle are all the items on the day. On the left is either categories (with links) or banners, or white space. On the right the same situation. So wherever you try to scroll there are always risks you're clicking on a link. Now if every link would suddenly become 20 pixels in each direction (top, right, bottom, left) wider it'd be even harder to scroll up or down.

But one can maybe notice if the user is scrolling or attemping to click a link. I'm not sure, but if one is scrolling I would say the finger makes a movement after a very short (say it is 100ms) moment of time whereas if the user wants to press a link she is more firm. That is where I want to go to. So there is hardly any, if any at all, movement in that case.