Not only that, but anybody old enough to have a Twitter account hears worse than that in the hallways of their school. (And occasionally in the Sultan household...)
I understand that, and believe me I use more than my share of foul language and heard it / spoke that way in school hallways too. Robinson did so in a public statement.
The problem I see now is younger people come into the work force thinking that is normal and acceptable discourse. Say that in the wrong setting, or in what you think is a harmless office email, and you will be in HR filling out paperwork rather quickly.