Many (not all) of the bloggers are not using there own material but simply using there blog to link someone else’s You-tune video with no original content.
They may he free to do so, but others are free to post the link directly.
Ahh but do you know why youtubers allow people to embed? Do you realize the person who uploads the video can stop people from embedding?
Most folks want their vids to go viral the more people embed it and the more points on the Internet it gets, makes it even more popular on youtube AND gets it a higher ranking on the search engines. When people subvert the process and post a link directly they prune branches off the viral tree. More branches the faster it goes viral!