Given how slow the format is, players can spend an enormous amount of mana to sc scry for lots of cards -- enough to make the ability worth using in make X a huge number and scry enough cards for it to be highly efffective with a 100-card deck
Adding White (Jeskai) has some merits as well
If your opponents have three or more artifacts and enchantments out, youre already pulling in a higher amount of mana than what you have put into casting it
Right now, Push is not shining anymore, due mostly to unholy heat that replaced Fatal Push as the best removal of the format since it can deal with planeswalkers too
Protection from Colors [c]Archon of Absolution[/c] has protection from white, so nobody can cast a white spell that targets it
Second, the cost reduction mechanic usually doesnt allow you to cast Karador super early (barring something like a Hermit Druid), but it does help you set up combo plays with creatures in your graveyard during the mid-late game