Hi there, mbin dev member here. I do not know melroy personally, but I have never gotten the vibe that he is egotistical or wants to make the project his own. Never heard that he contributed to Lemmy...
Btw. we do not have a lead dev. He is the repo owner though
The core problem I had with kbin was that Ernest is just the kind of person who likes to work alone and in his own ways. That is just not a good fit for a project that gets contributions from the community (which I think he is not interested in).
For example: I implemented a subscription panel in June/July 2023 and it got no reply from ernest for months. Then he replied once with the things he wanted changed and I did, then no reply anymore. I think it is still not implemented, but I lost intered. After I opened a PR about adding the same code to mbin I got some replies, answered them, changed the stuff that was complained about and voilá it got approved...
It is just not encouraging to contribute to a project where your changes get accepted after a year if you're lucky.
Mbin is just more open to people contributing.