Satire may have been instrumental in its own demise.

People see satire and are either smart enough to understand it - maybe even find it funny, or are offended by it. Those who are offended generally become more entrenched in their beliefs and those who aren't either don't see the satire for the warning it is, or do, but mostly choose not to do something about the subject.

And since people have seen what the satirised subject could be like, and they didn't take action, the subject might take the opportunity to move a little closer to the form it took in satire.

Given this and enough time, satire and reality can become indistinguishable.

And here we are.