This is the prime grievance that people have with Destruction as a kill skill: without enchantment abuse, it consumes too much magicka. Wheras crafting supplements other kill skills, Destruction needs it to be viable in the first place.
A perfect storm makes Destruction lacking:
Spells get worse and worse in regards to damage/magicka cost ratios as they climb in damage unless you commit enchanting abuse
Magicka regenerates agonizingly slowly, unless you commit enchanting abuse
And the cincher: You cannot deal any sort of damage with Destruction if you have insufficient magicka. With other kill skills, you can still do normal power attacks and get specials like sneak attacks or crit strikes or axe bleed damage or mace/hammer armor bypass, or enchant damage (if that hasn't run dry yet). Destruction... Empty magicka bar? Nada. Zilch. Zip.