Sad to see an important project's core maintainer leave but their justification seems very understandable. It is sad so much of OSS is maintained by very few as they alluded to in the XKCD comment, an especially given they felt the JVM ecosystem was causing them pain with limited support or feedback possible. I think it is always a little irresponsible to cause a great deal of breakage and not be there to support those who you break downstream of your project.