> By the same line of reasoning one should reject most code.

Yes, you should reject all unnecessary code. If that is "most", then your project might have some problems. ;)

> If/when the comment is obsolete, deleting it is easy.

The hard part is to know if and when the comment is obsolete. It's way too often I stumble upon comments that contradicts the code. Is the code wrong? Is the comment wrong? Often the history reveals that the comment was correct at some earlier time, but the person changing the code didn't think about changing the comment. I think that the mechanism behind this is that after the first read through of the code we tend to stop seeing the comments.