It may be in the public interest to cover but I would imagine it is not in the interests of anyone who works on the railway that people start fearing rail travel, cancelling plans, and so on, which is what I think broadcasting these horrific scenes achieves.
I'm sure that certain media outlets will be more than happy to accompany their footage with "are railways unsafe? would this have happened with automation? should you drive to work instead?", etc etc. Classic fear mongering, especially in light of the Bedford collision.
I think this explains why in this thread, people are trying to lessen the severity of this incident, perhaps they have an interest in people continuing to use the railways