In the past Curie accepted submission from everyone that wanted to submit, but that ended up leading to an enormous amount of spam, and bad submissions. The acceptance rating was extremely low. That was of course before my time here.
What they did afterwards is not to shut off others from being able to curate, but rather created a room in the discord channel where those that want to become curators have an opportunity to:

1. show their skill and dedication
2. show that they have an understanding of the guidelines and what makes a generally good post.

Thats actually how i became a curator, took me maybe a week and a half. And a lot more people have been accepted in the exact same way. You are free to go there and try it for yourself. :D

I dont understand how you mean that only a few benefit? Curie supports minnows everyday, it gave out more then $2mil in upvotes to quality creators. There is a ongoing feed on the discord channel where you can see who gets the upvotes.

Id wager that this "feed room" holds the highest quality content on any Steem related pages, discord channels, etc.