That seems to be a popular conclusion by people who are on the Trump side. I see little evidence for it in real life. Many factors go into a political choice, and sure, disliking Trump is one of them, but most Harris supporters would not be voting R in any case because they do not agree with that platform.
I don't know how many people are genuinely enthused about her platform. Mostly it feels like it's fueled by hating Trump's platform and Trump (which, to be clear, is a valid reason!). I guess I should have been clearer - I meant that they're voting Harris not because her platform is great (honestly it seems about average for Democratic candidates), but because they dislike Trump's platform and Trump himself. They don't really care what Harris is proposing, as long as it's vaguely reasonable.