Dude, this is how small Free and Open Source software projects work:
…and this article (among many, many others):
…and while you’re trying to create drama in this forum thread here and make it sound like you’re the victim of a great injustice, the pertinence of your proposed change was objectively unclear to onlookers like me as well, not just Frédéric.
While I’m the first in line to be frustrated by the “maintenance mode” nature of Kanboard’s development and some of its technical limitations (to the point where I am considering Tiki’s kanban board as a potential alternative that might be more scalable/better-integrated for my needs), I am even more frustrated by you throwing mud at Frédéric with your flippant attitude in that pull request (to the point where I felt compelled to comment over there) and in this forum thread. This is not the first time I see you coming in here with a monochromatic and confrontational attitude from the outset (as well as apparently expecting that most people would naturally be in agreement with you).
I’ve been contributing to F/LOSS projects for over 20 years and it never ceases to amaze me when I see such accusations being thrown at maintainers by people who can’t see how harsh their words are (and yet, I see people abusing open source project maintainers every day on bug trackers). Your “Having to justify ‘obvious’ changes is just wrong in the open source world.” statement that started this thread here is so out of touch with reality, it’s laughable in the eyes of any thick-skinned FLOSS veteran looking at this.
This is not to discourage you from attempting to contribute, but I believe you need to look at how you come off in your interactions.