That’s why it says “and the Lego Group” - you have to do the 10k and pass internal design review.
"Anyone who can convince the Lego Group", that could be said of any product/company!
It's like saying "anyone who can convince Netflix can launch a new TV Show".
No sense reviewing proposals for sets that can’t even get 10,000 people interested.
Bricklink is perhaps secretly (or perhaps not) owned by LEGO itself so they can have their hand in the pocket of the used / resale market. People will upload full MOCs (My Own Creation) there and you can purchase the sets piece-wise. Usually even more expensive than if you wait and buy a set through LEGO but for stuff like this it's worth it.
A speech, a monologue, can be convincing.