I wanted to ask about that, so thanks for anticipating the question :-)
I do agree that legitimacy/visibility is more of a concern than actual influence on conference content, but I wasn't sure we were on the same line.
Having clarified that, the visibility issue is shared by a lot of FOSS conferences (including #FOSDEM). It deserves: a) broader conversation than #CopyleftConf, b) sustainable alternatives (donations? higher registration fees? etc).