"comments tend to become outdated."
I have seen this happening often enough to know this can be a problem.
The thing is, I think I have seen
maybe two or three outdated comments
my entire career.
I believe it should be perfectly possible to work in an environment where everybody takes enough care of the comments and maintains them. It's just a small extra effort to look at comments near the code you are editing and update them when appropriate. In case the comments are so far away that you don't immediately notice them, they were bad comments anyway, and shouldn't have been added in the first place (or at least not there).
Furthermore usually along with the statement that comments tend to become outdated, follows the statement that this reduces readability and confuses people. This is something which I haven't experienced yet. Every time I encounter an out of date comment, I clearly see what changed and just update the comment accordingly to represent the newer code, albeit with some extra effort.
A recent study by Roehm et al. 2012 observes the following:
21 participants [out of 28] reported that they get their main
information from source code and inline comments whereas only four
stated that documentation is their main source of information.
This is in line with your suspicion that comments in the code itself generally are still considered to be very useful. This indicates that a clear line should be drawn between outdated documentation and outdated comments.
Roehm, T., Tiarks, R., Koschke, R., & Maalej, W. (2012, June). How do professional developers comprehend software?. In Proceedings of the 2012 International Conference on Software Engineering (pp. 255-265). IEEE Press.