I’m not disagreeing with you. You’re saying that the fediverse produces badly designed and branded services that mirror existing apps with massive user bases, that won’t be great until a lot of users migrate over. None of that is wrong! It’s why Lemmy is a mess that constantly breaks, and Reddit is still way more useful, even if most people here hate it.
It’s just that most Lemmy users care enough about decentralisation to ignore those product downsides, in the hope that they it can be overcome over time. With a messaging product, that’s even easier. You can just install it and wait until other users join - network effects are ’much more limited than with eg Lemmy.
The negativity was pretty asinine though. Nothing he said, I think, was wrong. I remember Mastodon people (rightfully) reacting quite annoyed at similar reports on how usage had peaked and was dropping again, just because not all the new users stuck around.