Morellonomicon

Bjerg did it, people blindly build two regardless of them actually needing the extra CDR or mana regen. It's fine on some champions, but not everything.

The item is just ridiculously cheap. That pile of stats should be costing over 3000 gold, but it doesn't. That's why it is so popular.

Double Morello gives everything a typical mage wants for 4.2k. Alternative builds are either much more expensive or provide less, if the champ can not abuse the special effects.

it just gives you an "earlier" power spike and 40%cdr and a ton of mana regen. otherwise it makes you get to late game much slower.