Why not allow the winner of the Women's world championship and the winner of the Junior world championship to join the candidates tournament? Their rating is lower than the top 10 players but I mean they are both champions . Also this would give extra motive for women to play chess since the winner of the Women's world championship would have a chance to play for the World Championship.
(this is my opinion, this is a purely opinion-based that some would say should be closed but I prefer to just give my answer)
It seems unfair and discriminatory to allow someone into the Candidates just because they are a woman or junior. The recent winners of both championships are also so far off the level of the Candidates that they just wouldn't belong there, and they would take the place of two players who would have qualified using the existing criteria.
All the ways of qualifying for the Candidates are open for everybody, man or woman, young or old. If the Women's champion wants to qualify for the Open championship, she can just try to qualify like everybody else.
This is not exactly the same thing, but on chess.com, they have allowed the women and the junior speed chess champion to be seeded into the open tournament. Well, the two women, who have played, Hou Yifan, and Elena Danielian have both been crushed by record scores, 27.-2.2 and 27-2 respectively.
The other day, Wei Yi got destroyed by Maxime Vachier-Lagrave 21-10.
In either case, and frankly, especially with the women, it would not be competitive. If you can get in on your strength of play, fine; but they should not be given free entry based on winning some other event. All this does is take away a slot from a more-deserving candidate.