I don't think that's necessarily the case. It's impossible for human curators to catch everything, as crawlers do. Lots of companies are inevitably going to be left off the list because their website is #2,000,000 in the world & they occupy some industrial niche. Those companies, should they want in, would not be buying entry, but applying for entry, and their application would be reviewed in accordance with certain rules and other criteria.

Blogs and forums could probably apply for free.

I imagine that the still-theoretical company would (hopefully) profit, and that the curators are neutral salaried employees, rather than Wiki-style volunteers.

Salaried employees have a bias to make their employer money in order to keep those jobs. For-profit companies likewise have a bias for money. That is where all the problems started with - bias for money. There is quite a bit of social nuance to this, and coming at it wanting to make a better internet while also wanting to profit from it are difficult goals to achieve together.