Why do people root for anything? Emotions, aesthetics, etc. You can't always stop yourself from having that reaction, so you may as well let it out. Myself, I'm rooting for the spacetime-from-entanglement family of quantum gravity theories, because they're frickin cool.
I'm rooting for the various dark matter particle candidates. It really seems completely unsurprising that there would be particles that react very little if at all to the EM field. It's true of other field and particle combinations. In short, I root for it because it's completely unsurprising. I'm great at parties btw.