A very long time ago I took over a FOSS project under GPL. It had pretty good support for plugins, a lot of demand for plugins, and exactly zero third-party plu

A very long time ago I took over a FOSS project under GPL. It had pretty good support for plugins, a lot of demand for plugins, and exactly zero third-party plugins that were even remotely maintained. I don't think we ever got many direct complaints about GPL, but our main assumption was that copy left contamination was pushing developers away. We wanted more open licensing to encourage wider adoption, so we started a replacement project under MIT license, I believe. Once the replacement project was in a good state, suddenly plugin developers started crawling out of the woodwork. My estimation is that about 30% of our trouble was due to licensing concerns, and the rest was down to the original project being in a very, very bad way. It was very old, had been abandoned by six developers, and about 70% of the code was unused and unusable. The new project had bells and whistles and was more attractive, but I think the open license definitely helped. You probably could have built a plugin without needing to use the GPL, but it would have been a lot more difficult. That whole project was a disaster, and I never once regretted letting it finally die.