Another fundamental problem with Mastodon: the federated and local timelines, that include all users, will naturally push users towards a more limited number of conversations, maybe only one or two. Marginal conversations, however interesting they may be, won't reach bigger audiences because of all the noise (on the other hand, abuse is less incentivised). This will limit the overall reach and potential of the network.
(Sorry for spamming, correcting a stupid mistake; Do add an edit button next)
@dgdas9 This assumes that the proliferation of Mastodon instances don't innovate. Ideally, once the initial novelty of running personally administered code-clones wears off, we may begin to see diversification as forks explore different filtering, curation, and network effect models.
@beadsland Seriously? If so, and, say I'm into Albanian soccer, German politics, and Irish rugby, I'd have to create handles on 3 different instances. That's why there's lists and hashtags, to allow for different conversations. And to some extent that's also here, but there is a bigger push for a centralised conversation. Curation of instances is not answer, it'd have to be followed for better inter-instance/inter-account support. And it makes mastodon more complicated, and it already is very!
@dgdas9 There is a difference between complication and complexity. The latter creates space for the new to emerge. The former only has space hobgoblins of conformity. It is far too early to say whether Mastodon is more one or the other, but I for one am hoping for complexity to be the quality to emerge from the stone soup we see today.

@beadsland I'll go for closing arguments as well. Appealing to the lowest common denominator is hard. It's not that people are more stupid than you think, they just don't care about it as much as you do. That's why you make things as simple as you possibly can.

Multiple instances are way too complex for undedicated users to care about. And what we're left with is a core product with a medium sized flaw that will hinder its growth and success potential, and more importantly, its usefulness.