As the GM, I can see why the two are designed the way they are, but the players struggle to see/understand the utility at a first glance. Since I haven't seen them in action I dunno how powerful they really are, but I think a good comparison is the Stop spell. It costs 10 MP and stops an enemy for a solid turn if it hits. Assuming an enemy removes this effect immediately (which a GM shouldn't do, I know, but players struggle to know that), that's wasted one of their turns, for double the MP cost. In a game where most fights last 4-5 rounds, that's important to think about when designing spells.