No, their utility is balanced by the research investment/cost in mage time/gem cost or whatever, especially if you want to wish (or other high level spell-spam.)
Why not attach a negative to clams, like horror mark, insanity, curse or disease? It creates a drawback, and also has the effect of taking some of them out of play over time. The problem now seems to be that there's no downside to the strategy (except for monotony, and people getting annoyed at you.)