I didn't get this from the post at all -- they didn't invent the vaccine, they're just trying a protocol put together by some other biologists they seem to trust.
The certifications and testing is not for show, and no one serious is claiming that. Asking an entire population to vaccinate is a huge responsibility; if you're making claims to the public that an injection is safe you'd better be as sure as you can reasonably be that it's true.
If you're just experimenting on yourself, the bar is lower: as here, you just need to convince yourself that your risk of adverse outcomes is very low.
An individual may be willing to accept a 0.1% risk of severe adverse outcome. A society that asks 300 million people to take that risk will experience 300,000 severe adverse outcomes.