First time I've looked at 538 (or any polling) since the election... Just on how corporate America and the media has been acting in the runup to his inauguration, you would expect his number to be at least 10 points higher
My hot take (which really isn't that hot honestly, but is treated like one these days) is that he was elected in spite of his flaws (not because of them), and that it is all primarily about the economy and inflation. Yet his fans, the media and Trump's team, for differing reasons, are all incentivized to look toward culture wars to explain it all away.