But why? I was reading a fairly vacuous art history book and they drop all this knowledge and then do 0 analysis of it. Feels like they’re saying “teehee, ain’t it so quirky?” Their best guess was to counter Socialist Realism and to promote the US as an art powerhouse, a vision of artistic freedom!!! Is that the materialist interpretation?
E: Thanks for all the thoughtful responses. Genuinely. When I write that it sounds corporate, but I mean it

The Socialist Realism policies were a strategic mistake that made enemies without much benefit, so by encouraging art movements wildly contrary to Socialist Realism, they could turn people against it because this perfectly fine art movement wasn’t allowed and perhaps even art that they like or would like to make was considered improper. That’s my interpretation of it, anyway.
Obviously encouraging Socialist Realism was a good thing, but discouraging other genres was counterproductive.