This is an ahistoric view of kale. Kale is a common food globally. I grew up eating kale in California, the highest producing state in the USA. There is a lot of cultural foodways sharing here and it's a model for us to do and be better.

Gentrification is a problem, but it's contrafactual to state that white people co-opted kale as a way to make that point, rather than a point of personal, regional, cultural experience.