If only Mastodon would spend time making the platform more usable, perhaps they would. e.g. the impersonation issue, which is much less of a problem on a non-federated platform, plus Bluesky takes a highly aggressive stance against it.
Also the enormous discoverability issue on Mastodon has lead people to say that "Mastodon seemed to actively discourage discoverability." This article seems very worth reading btw, as many of the same issues plague the Threadiverse as well - hostility to non-technical normies, hostility towards anyone less ideologically pure than oneself, hostility towards... wait, am I sensing a pattern here!?!:-P Early adoptors (who are proficient in using Arch Linux btw) are quite a very different crowd and while yes scientists are smart, they are also smart enough to realize that moving from a place where their work can be seen to a place where it will not be is not a very productive endeavor, in the short-term, for themselves.
Edit: also, when the tools go for years and years and years and years without ever getting any better at solving the issues that matter most to them, it sends a signal that they aren't welcomed. I will state that again, unequivocally: mainstream normies are not really welcomed onto the Fediverse. ... ... ... am I wrong there? Do we welcome them even here, on the Threadiverse, or are there a myriad of rules that are nowhere written down, must be discovered by each new person, all the while people talk down to them, criticize and even laugh at them, plus also laugh at them behind their backs when they go back to Reddit and share their experiences here, warning others not to come? From what I read at r/RedditAlternatives, this usually is b/c of facing "leftist" toxicity, which I put in quotes b/c it's not actually leftist, but it just seemed that way to them, since e.g. Hexbear makes no distinction b/c facts and reality, only what works inside their echo chambers that are then exported everywhere else they - and their alts - are allowed to go. But please feel free to visit that subreddit and verify all of this for yourself.
Here is some additional evidence: (1) at https://mander.xyz/c/science, the top-most link points to a lemmy.ml community. Is lemmy.ml known at all for its stance on "facts" vs. "alternative facts", and in particular which facts are allowed to be shared or not? This is a choice by mander.xyz to feature that particular link though. (2) look at https://join-lemmy.org/, and pay close attention to the very first image on the screen. "Landlord Love", "Tankie..." - yes this is a screenshot from lemmy.ml. Does that instance make people in the Western world feel comfortable when they visit it - especially mainstream normies... or even scientists, who often trend toward liberal but even more aim to stay out of politics altogether, in order to more closely focus on science? The words on that page also are things like "mod tools" and "host your own server", not things like "a place to discuss topics of interest". That site helps people who want to become admins more than those who want to become a casual user - i.e. an early-adopter, Linux-using, config-file-editing crowd, not a bench scientist grad student who just wants to chat about science.
This is the part where you say "but mander.xyz does not itself espouse tankie beliefs and philosophy - I mean yes in truth it actually does promote that e.g. by putting in those links, but it does not PROMOTE promote that, not REALLY!? (not directly at least)" In which case bam, now you understand why scientists continue to use X rather than spend time learning how to make use of Mastodon. Everyone does what is easiest and they feel is best for them. We do not really reach out to make them feel welcomed, so they find it easier to simply stay where they already are.
