What Will said was pretty much true.
Em has always been about shock value and that line he said proves it.
"Will Smith Don't Gotta Cuss In His Raps To Sell Records, Well I Do So fukk Him & fukk You Too"
While I don't disagree that his shock content helped him get to get where he's at, that line is satirical (whereas you're making it sound like "see - even he admits it"). That line doesn't prove anything.
He's always saying things like that and pokes fun at himself, and also says a lot of lines in a way where he's mocking critics/objectors while saying "I am that way" or "ok, I'll do that"
This is another example where he's doing that, and sort of twisting what someone else said and spitting it back at them, all while saying "you're right."
In response to ICP's Slim Anus diss song:
"Slim Anus? You damn right, slim anus
I don't get fukked in mine like you two little flaming fakkits"
Another similar kind of line
"here, want me to tone it down?
[in a lowered voice]
Suck my fukking dikk, you fakkit, you happy now?"