Minions aren't "needed" for anything. Some items should be hard to get. As a collector myself, it feels nice to have something special that not everyone else has. I'd rather tear my hair out getting it and have it actually be rare than to get it day 1 along with every other person in the world. I like the minions part of the game as is: some are easy, some are a bit harder, some are fairly rare, and then some are crazy hard to get. The Onion Knight falls in the latter category. Oooooh well.