everyone

It's the everyone part. You need to get everyone on board. That is A LOT of ducks to line up; to put it lightly. Forcing it via prohibitions without first addressing the underlying needs;

1. incentivizes non participation by both opponents who stand to lose and would-be supporters negatively effected by my 2nd point.

2. Has unforeseen outcomes resulting the same working class casualties we wanted to avoid in the first place

Basically it's easier said than done and there's no shortcuts like, 'outlawing for-profit". There are real logistical challenges are completely outside of capitalism at play. We have to do the hard work of building a self sustaining society first. Than we can remove vestigial constructs like capital and profit.