You keep repeating this advice from the beginning of this thread. However, it is contrary to:
1. The tests posted in this thread so far
2. Claims in the article referenced by Hans, Andrew (digitaldog) and me more than three times in this thread
1. The "test", don't you mean? The "test" that some of us are trying to tell you is invalid?
2. You are misreading that statement on that page (and Jeremy tried to correct you on this, too.) You are reading it with the emphasis on the word "untagged". GBallard, however, is meaning to put the emphasis on "sRGB". In other words, he is saying that of the 3 untagged examples in sRGB, AdobeRGB, and AppleRGB, the untagged
sRGB image will be the closest to the properly color-managed image on the left for
MOST PEOPLE. The reason he says "MOST PEOPLE" is because those with wide-gamut monitors (or with monitor profiles that have heavy corrections) will NOT see them as the same.
John and others in this thread have made a valid point. It is good practice to embed the profile and this will be only more important in the future as more and more people have monitors that deviate from the sRGB gamut. As far as I know, the only rationale for NOT embedding is to save a few kb of file size but that is no longer a big deal unless you are doing some kind of application where you have 1,000s of very small images (like icons, for example).