I didn't wanted to blame anyone.I'm not sure it's useful to talk about myths and mistakes to be corrected
When I first realized some years ago, that one of the second hand accordions I just bought is tuned to 443, I got quite confused. I found posts like the ones I cited above and though: maybe its not so bad. I even brought the box a few time to some gigs. I don't think anyone realized that it was out of tune, but I also don't think it was standing out particularly.
Since then I have been stumping over this tuning your accordion higher to stand out theory again and again, e.g. just yesterday someone wrote it in a discussion on Facebook. So I wanted to know whether there is anything about it.