It's a good observation, but probably a bad example since that page is clear on what criteria they consider for something to be "safe".

That aside, of course DJB would choose criteria that let him label his own curve as "safe".

I'm no cryptographer so ultimately I have no choice but to rely on others' expertise, but that does not mean I take at face value the words of someone talking about their own project. Probably for the same reason HN requires disclosure when talking about something you're involved in.