Is there a particular reason that none of the post-shards builds this past page seem to be running Qasali Pridemage?

The flexibility it offers is absurd.

Your opponents basically can't play Counterbalance or Standstill as long as you have it on the table. And it blows up Oblivion Rings, Veldalken Shackles and a huge number of other artifacts and enchantments that just about every deck plays.

It beats for 3.

It wins you Goyf stalemates.

And it only costs 2 mana (cheaper than Oblivion Ring). A walking beating Seal of Primoridium, what more could you possibly ask for?

My creaturebase would probably consist of...

4x Qasali Pridemage
4x Tarmogoyf
4x Lorescale Coatl
2x Sower of Temptation

The Coatl could be cut for Mystic Enforcer or Jenara and/or maybe Rhox War Monk or Trygon Predator or Meddling Mage or Nimble Mongoose or Noble Hierach or something. But the Pridemage seems like it should be a staple in the deck.