... because they need to.
They can't back down now and admit they're wrong, of course, but it's more than that ...
... it's because it's too threatening to their psyche - what it would mean about them, if they made false accusations about innocent people over politics and the bad things happened to those people as a direct result of those false accusations.
Thus, even if proven wrong in a court of law - like Alex Jones was - they will continue to believe their own lies until their dying day, despite lack of any proof - even tacking on more false accusations as justification (which often become more OTT and bizarre over time).
All because such individuals cannot regulate the emotion of guilt, they (if ever or still capable of guilt) - to combat feeling any guilt - so that they never have to come to terms with the fact that they were wrong, and what happened to the lives of the people they falsely accused as a result - and what doing so means about themselves.
And it's not just individuals - you can see it in groups, on a small scale, like a cult - but even in everyday situations, like a dysfunctional family or a toxic/bullying work environment or group cyberbullying online.
You can even see this on a large scale, like the Nazis or Pol Pot communists or followers of Idi Amin - in fact, we're seeing it now with Russia and the Ukraine, the Russian propaganda and victim-blaming.
Of course, there's something to be said for fear-based propaganda and "induced" sociopathy, a process which we don't yet fully understand, as well as "suspension of morality" in these examples - studies which have proven the latter especially.
However, the group leader(s) are always themselves true sociopaths/psychopaths - true monsters.
Regardless, presenting evidence to the contrary or trying to reason with them will do no good - in fact, it only makes them angrier and more entrenched - much like arguing with a drunk or a dysfunctional family member - and that is because they don't want to see the truth, they need to believe otherwise, for the reasons stated above.
So we have to let them continue to believe it ... let go and let God ... because if nothing else, these fellow self-proposed "Christians" also claim to believe in a higher power - and thus will have to argue their case before their maker, at some point - and it won't be pretty ;).
Because in addition to Christ's warning parable of the merciless servant in Matthew 18, God himself wasn't such a fan of bearing false witness - it's one of the 10 commandments (Exodus 20) . And John in Revelations 12 hints at a final consequence for consciously false accusers
But have a good day anyway? lol