The ones who offered fee waiver programs weren't on his list, because they weren't predatory. For example, PNAS may not be a great journal, but it's OpenAcess and not predatory... hundreds of others with very similar names to high profile journals and fake conferences are predatory.

I wouldn't say that it's rare to have to pay (even for a non-free journal)... in fact it may be more common to pay just based on the number of predatory journals and their published articles, it just isn't ethical (either for the publisher or often for the writer).