I've had a similar, although not as extremely bad, experience to you. It does make the project look bad, but I've actually run into this issue with lots of stuff where "stable" is horrendous to use (Debian) and gives the whole project a bad name. I wouldn't mind recommending spacemacs to a friend around my age, but I guess the issue of having to be on develop is something that would make me hesitant to recommend it to my parents (something I've genuinely considered, by the way).
I also frequently wonder how I'd introduce spacemacs to someone who hasn't used vim or emacs... I used vim for a very long time, so to me it's great that my knowledge carries over. I just don't know if it makes complete sense to say to someone "vim has better bindings than emacs, so even though this is emacs, you should learn these vim binds". Plus then they should probably still know at least the basics of emacs for screens where evil fails you, or for if they ever have to use emacs on another machine, or for when an emacs bind is better ("C-x h" seems better than ggVG to me).
I also frequently wonder how I'd introduce spacemacs to someone who hasn't used vim or emacs... I used vim for a very long time, so to me it's great that my knowledge carries over. I just don't know if it makes complete sense to say to someone "vim has better bindings than emacs, so even though this is emacs, you should learn these vim binds". Plus then they should probably still know at least the basics of emacs for screens where evil fails you, or for if they ever have to use emacs on another machine, or for when an emacs bind is better ("C-x h" seems better than ggVG to me).