Amusing, but I would prefer something that would be able to automatically know what I was meaning to do and just do it without having to be vulgar.
~> wtf is imnsho
IMNSHO: in my not so humble opinion
~> wtf is cat
SVK::Command::Cat(3pm) - Output the file from depot
cat(1) - concatenate and print files
fc-cat(1) - read font information cache files
git-cat-file(1) - Provide content or type and size information for repository objects
~> wtf is fuck
fuck: nothing appropriate
Vulgarity of expressions is not a function only of what the expression means, but of the acceptability of the expression itself in various social contexts. WTF is, generally, acceptable as not excessively vulgar in social contexts where expanding the last letter of the initialism into its referent would not be, but the reverse isn't true; WTF is pretty close, therefore, to strictly less vulgar.
This may not seem rational, but then the entire concept of vulgarity is irrational.
Which social contexts? Social contexts where people don't know what "WTF" expands to? It's not even a "minced oath".
"The f-word" is used exclusively by people being descriptive. Nobody says "So I was f-wording my spouse..." or stubs their toe and exclaims "oh f-word!". It is used when people are reporting what other people said. That is why it is considered less offensive; it is never properly used.
It signals to the easily offended, "I want to convey this information to you, but I am deliberately mangling words so that you know I too disapprove of the terrible word that was unfortunately used by somebody else."
"WTF" isn't used that way. When people say it, they are using it, not describing somebody's usage. There is zero implication of an apology or empathy with the audience's word-phobia.