Keane from YouTube announced in a YouTube Help thread that they decided to remove the tags from showing up on the video watch page because some are abusing it.
Keane said it wasn’t used much by the average user and when used, it was typically abused by being copied from video to video. He wrote:
In no way does this mean you should not tag your videos. YouTube will continue to use it for discovery and search purposes. Keane explained:
Forum discussion at YouTube Help.
