Yea, and a toggle for showing some text or not (which is already there for subtitles anyway) is even way simpler than a profanity bleep option.
The former takes about 10 lines of code to write. The latter would require someone to go through all the voice recordings with profanities, flag them, write down the exact time and length of the word in question, then write an extra track in the dialogue system for the bleep, that then gets played back at the exact right time and length.
I don't know about Frostbite but at least in UE3 (if you did this for the trilogy) there was no system in place for one sound to overwrite another and then let it smoothly go back to the original, so an entire class would have to be custom written for that feature as well.
So yea, this is one toggle I'd rather try and avoid, if I were developing the game (which gets rated M anyway).
EDIT: I will admit that it would probably be less work than translating Windows into Welsh though. 
10 lines of code?
10 lines of code?
People really shouldn't say things when they have no idea what they are talking about. Try:
10 lines of code to add the toggle to the options menu
x lines of code in EVERY SINGLE CONVERSATION IN THE GAME to swap out dialog files for the 'clean' version.
x lines of code and x hours spent adjusting cutscenes to hide 'objectionable images'
x hour spent analyzing what needs to be censored, when
x hours spent going through each line of spoken or written text in the game to ensure no objectionable content is missed
x hours spent remastering dialog files to add bleeps
x hours spent making sure the newly bleeped lines still match the cutscene as far as lip syncing and timing go
x hours spent testing to make sure the right lines play, display at the right times according the the dam.. err I mean darn toggle.
all to find out people complain that they didn't edit out #!@$ because they didn't consider it objectionable enough.
10 lines my lily white @$$