I do think they should allow users to customise the CSS to their heart's content, though, it shouldn't be that hard to supply a user editable stylesheet.
The complaints I'd heard don't seem to be that accurate - it certainly doesn't seem illegible. Although it has infinite scrolling (which I dislike) there is a promise that pagingation will still exist for those who want it. There is a lot of white space, but that only bothers me in cases like Andrew Ducker's links lists, otherwise I have no issue. Complaints that "if I go away I'll have to scroll forever to see what happened while I was gone" are erroneous - you now have easier than ever access to seeing your friends list for an exact day using the now more visible calendar features. The "up" button is implemented well to show when updates appear. Personally I think the default is an improvement. I do, though, think that it should be user-customisable.