I could imagine one or two copies as an aggressive one-drop that allows you to swarm a large blocker
If Cursed Scroll is good in your deck then this is likely not that much worse than Myr Enforcer
For example, suppose you control Infesting Radroach, a 2/2 creature
Meanwhile, against some of the best creatures to exile (Heliod, Sun-Crowned, Uro, Titan of Nature's Wrath, Kroxa, Titan of Death's Hunger), you're losing almost a third of your starting life total, which is extremely painful
Combining low-cost instant and sorcery spells with mana from Treasures lets you filter through your deck until you find win-condition cards like Crackle with Power
There were a bunch of themes that encouraged you toward including certain cards in your deck, but there wasn't a mechanic that was pushing you to make interesting in-game choices