If you look it this way: "Pull 6 cards from your deck and play them all" - yeah, it sounds bad. But it's usualy not 6 cards at all, to me vs Secret Paladin it was ~3 cards on average, that cost 1 mana each (and that aren't op at all) and that all gets played the same turn since he cannot control when they are activated, but rather it's their opponent who control when those cards are played. Also vs a lot of control decks it actually helps opponent win because you outdeck with it.
It's not like Secret Paladin is invulnerable because of this, it makes the deck go round and it is essentially very good card but it isn't really all that insane as I read here, nerf Dr. Boom for example but this isn't that big of a deal I think... at least it looks like that to me.