Missing the point.
He isn't saying that there's a problem with people looking at pornography in public. His argument, and that of the Children's Charities Coalition on Internet Safety who are the real force behind this announcement, is that blocking pornography is required to protect children from accidentially stumbling across images that might scar their innocent little minds. This is the internet - risque advertising, frank discussion of sexuality, and lots of trolls who like plastering porn all over public forums just as a joke.
It won't end here, of course. Block porn now, and next year there will be calls to block sites containing racism or religious hatered, then libelous content, sites promoting copyright infringement, sites explaining how to get around the censorship, pro-suicide sites, unregulated forums... anything not suitable for ages three and up.