Hey Gerald!
Let's go through your arguments.
"I happen to find the project really cool. I don't consider this spam since it comes the heart."
I have never seen spam or even advertising being defined as not coming from the heart. I am sure many advertisements are made by people who truly believe that the products they advertise are great. Their messages are still advertisements.
I also don't consider advertising to be inherently bad or unnecessary. But it has to be present only at spots where people have specifically agreed to display it. I don't remember a LAU mailing list rule that says "Please feel free to post messages about your friends' Kickstarter campaigns or other messages, unrelated to Linux Audio". If such a rule is there, please point me to it.
"If you are not interested, fine."
I am glad you approve.
"But maybe others on this list are, just like others share stuff that interests them. Yes most of the posts are music-related."
Not most. All of the posts on this list are related to Linux Audio software and music produced with such software. This is the first time in all the years I'm on this list that I see someone posting an unrelated message and then even defending their right to do so "from time to time".
"However it doesn't harm this list if non music related news is shared from time to time. It prevents narrow-sight ;)"
I disagree. Maybe someone has a problem with "narrow-sight", but I have many informational channels apart from this mailing list and I believe my interests in life are varied enough to not require people to push their friend's kickstarters to me though thematic mailing lists.
Again - this mailing list is there to share and inform on LAU related items. Anything else should not be posted.
In fact, I am astonished that none of the admins of the list have spoken out.
p.s.: your friends Kickstarter is nice, but you are doing his project a disservice. Even if I was interested, I would probably not support it after your behavior.