It's a vicious cycle: sellers of French cards get lower prices, which feeds the perception that French cards "are worth less"
I'm not sure there's a good answer for this one, but I want to acknowledge that this was, by far, the number one complaint I got about the set
For just [1W], you can swing for 30 damage, but if Keldeo ex moved from the Bench to the Active Spot that turn, the attack jumps up to 120 damage
Triumph of the Hordes is one of the best green cards in MTG if you want to steal games out of nowhere
Monk Class There was a cycle of five 2-color class cards at rare in the original Forgotten Realms set, each in one of the enemy combos
The Deck (the original deck which personified the card-advantage strategy) packed the Tome as a way to gain card advantage steadily throughout the game