If life hands you lemons, make lemonade.
If life puts you in charge of defending a gold mining operation and you are only a mage....well
Magic is like alcohol, the more that is used, the more it causes a hangover later on and the less judgement one has when using it. If one waits a while after casting a spell, things "detoxify." A cantrip or two is like a sip of weak beer, whilst a large creation spell is like a bottle of vodka. Cast something too big and you can die from magic intoxication.