We all know Western Civilization has fallen to Fascism, so why not just come out and announce it?
Because compulsive lying is one of the classic symptoms of sociopathy. Every oppressive regime lies. They don't believe their own lies, and they know nobody else does either. They do so anyway, because getting people to repeat lies makes them their own jailers. The system can't jail or kill everyone, and in fact can't do anything on its own; it must convince someone else - a police, a soldier, whatevever - to deal with threats on its behalf. As soon as those agents lose their loyalty - as soon as they admit to themselves they're only putting up a show to keep from getting killed themselves - the system has already fallen. It has no power anymore, just an empty shell of it.
The scond reason is that fascism is basically reactionary. It originated as an attempt to stop the spread of communism at a time when liberal capitalism seemed to have failed. For any Western nation to openly embrace fascism again would mean admitting the economic policy of the last few decades has been an utter failure. But that policy was not just a pragmatic project but a matter of ideology to a lot of people. And ideology is just secularized religion for the materialistic era. To admit its failure would be apostacy. Just look at McCarthy's witch hunts; anyone can see they're exactly that, even if conducted in the name of a secular ideology and state.
And of course the third is that Western Civilization is not currently fascist. We wouldn't be talking about this openly on a public forum if it was. Increased surveillance by various intelligence agencies is worrisome and could potentially lead us to an unpleasant place once again, but we're nowhere near it yet. Not every political decision you don't like is a sign of fascism any more than every shoulder ache is a sign of a heart attack.