To most, it is, indeed, a mystery.
Hou Yifan preparing to replace Judit Polgar as Women's #1?

Judit Polgar has retired from competitive chess for a while now.
That just makes her look even better.

Worry about ratings AFTER a tournament, not during it. So, Hou lost to Kramnik. It's not a big deal. Let's see how she does for the rest of the tournament.

Not doing so well in Qatar.
Being ahead of World's #2 100 rating points, you certainly are a bit indifferent about your rating...

Not doing so well in Qatar.
Being ahead of World's #2 100 rating points, you certainly are a bit indifferent about your rating...
She's 100 rating points ahead of Kramnik?
to cut a long story short, you don't always play at your current peak. one of the mysteries of the universe has been revealed.