All sites need to quit using third party services. Most of these sites run WordPress and there are plenty of open source commenting plugins to use if they don’t want to use wordpress’ built in commenting system. wpDisquz is a good one. All comments and users get kept in your own database that way.
Videos can be uploaded and served from their own server with a standalone video player instead of embedding youtube.
Infowars lost their commenting system because they used Disqus and youtube banned them. Their site ended up looking very low tech after that.
You do make some good points.
A problem is that hosting comments can become very server intensive, and streaming media can become exorbitantly intensive — normal webservers aren’t optimized to stream videos.
But again, you do have a good point.
On a different note, I’m looking at using Epik.com for some of the sites I work with.