It's got a hopeful tone, but I'm a bit confused by his advice to ignore mastodon. The fediverse is more than just mastodon. Mastodon is just one use of ActivityPub. If anything exemplifies the DIY nature he's trying to promote it would seem to be the fediverse.

My take was that he was saying ignore Mastodon like you would/should ignore Twitter - that platform isn't conducive to constructive online interaction.

"When you tell me about Twitter vs. Mastodon, I hear that you got rid of the flesh-eating piranhas and replaced them with federated flesh-eating piranhas. No thanks, I’m still not swimming in that pool!"

That doesn't refute that Mastodon is only one part of the Fediverse, nor does it address that federation actually changes the behavior of the social graph (in contrast to centralized Twitter) due to where the power to moderate and block lies.

It's not as simple as "the interface is similar, so Mastodon is a (federated) replacement for Twitter."

Why would it refute that? No-one said Mastodon is the Fediverse. The author is talking about Mastodon specifically.

Yeah, that has not been my experience on mastodon (the "flesh-eathing piranhas" bit). It's much more civil likely due to the fact that algorithms aren't boosting outrage on mastodon like they are on twitter. Sure, the user interface looks superficially similar to twitter, but the user experience is much different.