His base is made up mostly of young college students, who haven't spent a day in the real world. They're also his loudest and most obnoxious supporters by far.
Regardless, the simple fact is he couldn't garner enough support to beat Biden. There's no conspiracy, or brainwashing behind it. He's just not as popular as you seem to think he is. Socialism in general, is not as popular you seem to think it is. On top of that, he's old as fuck, and suffered a heart attack during the primaries. Not a great motivating factor for voters.
He lost. Get over it. You guys are getting worse than Hillary supporters, with all your excuses.