If you are a high quality developer, you want your code to be correct.
This means you are not threatened by a review finding bugs--you
*want* a review, so anything you missed gets found. The code you
check in under your name is something to take pride in, and you
don't want your commit to be the one with a bug in it.
That being said, my experience has been that most people don't
know how (or have the patience) to do a good, thorough review.
Time gets spent commenting (and arguing) about superficial things
rather than understanding and verifying meaning embedded in the
code under review.
It's unfortunate, because time spent doing a good code review is
*much* more productive than the aggregate time spent (by customers,
support, and ultimately developers) on bugs found in the field. The
cost of bugs rises incredibly quickly the later they are found.
So code review is very important, but (like code) if it's not done
well it's just not that valuable, and may do more harm than good.