Well, he’s got a point in the first part you quoted.

Most “regular” people, the not-techies, are simply not interested in the technology or ideology behind a product. And Mastodon is a product in that sense.

What counts for most people is convenience, price and utilitity. If Mastodon adds complexity to the usage or lacks the content momentum, it’s simply not attractive to most regular people. And that’s not a hurr-durrr normies stupid rant, that’s how most people feel about most things. You probably don’t really care, how the oats in your oatmeal were produced, or your shirt, etc. You may would choose the morally superior one of you’d have the choice, but would you go out of your way to find that product?

Whether that counts as “failing” is a completely different question. But if the mission of Mastodon is to take over the position Twitter and Facebook have today, well then there’s definitely a good chance it’s failing that mission.