Negan is famous for two things: bashing people's heads in and his liberal use of the F-word.
Looks like AMC is going a bit more lenient on the use of the word this season, as we get to hear Jeffrey Dean Morgan use the word twice this season. This was confirmed at The Walking Dead panel at NYCC 2017 this evening. If there's a character that should get to say it more than once, it is Negan, after all.
AMC seems to be following suit of other cable networks like FX, who throw out that word a bit more frequently than other networks. Maybe someday we can hear an entire speech like the ones he gives in the comics — that will really send adults flying to throw earmuffs on their kids' ears as they watch.