I don’t see anything wrong with what the word describes, the act of fucking is a normal and natural thing to me. If it is supposed to be a bad word because the thing it describes is bad, I would suggest to all that fuck be made a normal word, and instead be replaced with the words pedophile and/or rape. If it is seen as a bad word simply because so many people see it as a bad word, then I would say present logical reasons why it is bad, or stop saying it is bad, so to avoid appeal to popularity fallacies.
I would argue that not only is the word not a bad word, but that it is useful, and when used properly serves to enhance your vocabulary.
There are some times when it should not be used, for example, some people replace ummm and errr with fuck. e.g. “the other day i was hungry, so i went to errm you know, fucking whats it called, the shop” In this case it is a bad word, but only because of the context, the words “apple” and “shoe” would have been just as bad in its place.
To me, the word fuck can help emphasize things, for example, if i tell you my friend is crazy you wont think he is as crazy as my other friend who is absolutely fucking crazy, and if i tell you im angry you wont think im as angry as the other day when i was really fucking angry.
It also helps modify meanings, for example, “what is wrong with you?” sounds like im asking someone who is rolling round the floor in pain what their injury is, where if i say “what is fucking wrong with you?” it sounds like im asking someone to justify their actions.
To me, vulgar language is different, its all about meaning and context. to me “I would really like to fuck that hot gogo dancer” is simply a statement of fact, and the statement “I really love sticking my cock in little girls” is vulgar, as the thing it describes is immoral.
As for insults, they need to make a claim of some kind, and be at least 50% not true. for example “fuck you” makes no claim, and as such cant be tested for truth. however, “you always lie” does make a claim, and you could determine if the person does lie. If they do lie, then its just a statement of fact, if they dont lie, then you just made a slanderous insult against them.
That’s more or less my view on the subject.