Not all the people who didn't vote for Harris are Trump supporters; there are a lot of leftists and progressives who believe that they can't survive any more late-stage capitalism. They recognize that the only peaceful chance to stop the wealthiest 1% from ruling is to stop electing them and stop electing the people who are bought by them.
Corporate democrats are better on certain social issues but they'll still put wealth over people, and they'll never move left. It's why we have the cruel health system we have today. It's why the banks got bailed out and never got regulated. It's why the Digital Millennium Copyright Act passed. Heck, 81 Congressional house democrats just voted for a military spending bill that denies medical care to trans kids.
Kamala Harris is a corporate democrat.
I actually voted both third party and for Harris, so maybe don't assume you know how people voted or what they want.