I didn't downvote but for a lot of the time the core devs were mostly 1-2 ppl working some evenings because they have dayjobs/lives. They released many updates to 2.10, and they're often feature releases not just bugfix releases. At the same time they almost completely rewrote the backend to use a new graphics library GEGL, which they also wrote from scratch. As for GIMP 3 they have also redone a lot under the hood to allow for easier development of new features moving forward and custom old GTK widgets updating to GTK3 required rearchitecturing as they work fundamentally differently from modern GTK3/4 versions.
So that's why I don't joke, there's also nothing to forgive. Let's hope that GIMP 3 will get more interest from devs with its more modern and capable architecture.