I think the main issue is bait and switch. You start with a license, get lots of external contributors who are working for free, get ecosystem built around it for free and then change because you want to be paid.
Does it matter if you intended to do something nefarious all along, or if you just now saw an opportunity to be nefarious? All that matters is that you are doing something nefarious.
I'm not sure how nefarious this Redis move was. I guess I was assuming any move from 'free', to 'paid', will be met with some outcry regardless of how seamless they can pull it off.
Or in other words, it is always a messy transition?
