What we're seeing here is one embittered ex-developer spending time/effort saying toxic things about their former collaborators in a public forum. At the same time the former developer is making a claim to such radical competence that they can somehow keep an open source project of considerable scope together -- one which until now was coded by generally at least half a dozen committed authors at any given time. The darktable project was originated by some quite bright folks. Others have cycled in/out over the years. Generally without too much drama. It's too bad to be giving so much attention to divisive claims.