I just removed a bunch of stuff from my Careers profile, and went to look at the public view to see what it looked like now. Over to the right below my Gravatar, it still said "profile updated on Nov 6, 2012" but this is clearly inaccurate as I just made changes to it, which are all present on my current profile.
Then I added an answer to my list of answers to see if it would update, and it immediately changed to "profile updated today". Why does removing things not count as "updating" your profile? Your profile is still changing, even if there's less information on it now.