See Ars Technica graphic below:

Now I can see a lot of resons for this -- one being that Internet journalism is largely citizen journalism -- without legal departments to censor the skank comments.
But whether explainable or not, it is a troubling trend in that Internet journalism is the only category not dominated in the US by five media giants. Silencing this channel would strike a terrible blow to having a truly informed society.
Thanks for reading, and don't forget to write.