That's part of it. The bigger reason, I believe, is that day is one of the ugliest domestic events in our nation's history and it was by folks from their side of the aisle. To be clear, it pales bigly to some other events like the Civil War, slavery, etc. but it was big. Not just the storming of the Capitol, but Trump's grand scheme of trying to get Pence to unilaterally dump Biden electors. These morons can deny it until their black hearts stop beating, but that truly would have been the end of America had Trump, the loser of a presidential election, been installed in the White House. And that is what the seditionists were fighting for.
So to mitigate guilt by association, they try to blame the left for it if it happened or deny that it happened when they can't actually find anyone on the left involved. And because it's a cult, they believe whatever Trump tells them. They've truly surrendered their interest in thinking for themselves and look to him (and fake news) for guidance instead because they truly believe only he can save America from the abyss the delude themselves into believing this country has become. A big part of it is the fake news media they've been Pavloved into believing which not only sells them fake news, but also convinces them not to accept any other news sources. I honestly don't see a way out of this death spiral unless they experience a mass awakening some day.