Whilst I haven't read the entire article, the first paragraph is actually on-point: apartheid was shit in a lot of respects, but the schools, especially in rural areas, have dramatically declined since 1994, as have most government-run companies (with the exceptions like Eskom being bailed out every year).
You don't have to like the facts, but that's what they are.
Saying "advancements in black literacy and real wages during the era" as if those things are due to apartheid is offensively absurd.
How about we advance literacy and wages without, you know, all the apartheid.
"I think we gotta hand it to Apartheid because schools were very slightly less worse" isn't the argument you think it is. It does paint where you stand quite clearly.
Never start a sentence with "I'm no apartheid apologist, but". Nothing good can ever come out of it.
So, ask the rest of Africa how that has gone for them.