Obviously its not really worth spending two mana and a card to turn your worst creature into the best creature on the battlefield, but what about a spell that can either do that or turn your opponents best creature into the worst creature on the battlefield
When it's restricted, do you really plan for it
Elder Vampires are clearly no joke, and once Insidious Mist is flipped, its very difficult to get rid of it
I guess it's the combination of cards which are either burn (and therefore, valued, in terms of "AI Base Value") and/or cards that are expensive in real life (Mana Vault, Wheel of Fortune, Mana Flare, Lightning Bolt, Fireball, Disintegrate) that makes the scoring algorithm give such a high value to that deck
The legendary land Miren, the Moaning Well ETBs untapped, taps for colorless and then with three to sac your dork and gain life equal to its toughness -great here
Doing connected cards prevented us from balancing the colors, but as Set Boosters weren't being played in Limited, it wasn't considered a big deal