Hey Erika,
It feels especially penalizing after having an event achievement that required use of runes. The most recent event really highlighted how counterintuitive the current solvent system is to your vision of the game being able to constantly try new configurations and builds. Realistically, no one is really using Mr. Boggins, and with the very real scarcity of runes, it just feels really bad to have to use a solvent to access the rune, put it on a crusader for an achievement with zero chance of long term use, and then another solvent to free up the rune again for effective use.
The event achievements can be completed at any time, unless it's one of the odd ones that require being on the event objectives themselves.
Plus, there's the talents that want runes equipped on all Crusaders now.