That would mean effectively surrendering the ability to ever make money back for time I've put into drawing the font, so I'm not entirely sure why I would want to do so?
Edit: non-profit license vaguely maps to CC-BY-NC though.
Sorry, but I don't follow the reasoning. Wouldn't proprietary projects be incompatible with the CC-BY-SA? Such projects would still have to pay you to use the font. I thought it was a "GPL-like" license for creative works.