While Puerto Ricans are extremely self-consciousabout their "Spanish" accents in English, heavy English"accents" in Spanish are perfectly acceptable for Whites,even when Spanish speakers experience them as "like afingernail on the blackboard."
The main point of this article is that Mock Spanish is used in the White public space and it's considered "acceptable" to Whites, but in reality it's a covert form of racism.
This passage supports the argument by exemplifying Mock Spanish in the white public space. For example, Puerto Ricans may feel self-conscious of their accents in English, whereas for Whites having accents in Spanish is allowable and considered fine to them.