There's a huge difference between something that is presented in an easily accessible settings menu, and something that requires you to go to an esoteric page, click through a scary warning message, and then search for esoteric settings... Before even installing a server.

Nothing was compelling Mozilla to rush this through. In addition, nobody was asking Mozilla for remote access to AI, AFAIK. Before Mozilla pushed for it, people were praising them for resisting the temptation to follow the flock. They could have waited and provided better defaults.

Or just wedged it into an extension, something they're currently doing anyway.