im playing a pure mage and so far destruction seems fine why are so meany ppl saying its broken?

Because when you're level 50 you'll still be doing the same amount of damage while people dual wielding steel weapons are one shotting Alduin.

Because your spell damage wont go up with your spell skill. Im playing a pure mage and now at level 45, the only thing keeping me viable in damage is either exploiting potions to boost destruction or use other schools that are more effective. And I WANT to be a desctruction mage, lobbing fire and lightning spells around but they just dont do enough damage when you get in to the thick of it. Try fighting a low leveled dragon from range with only lightning bolt. Then try it again with an atronach and notice how much faster & easier it was and note the manna it took to get the job done.

Destruction is mostly fine. Its the crafting system that is broken (in that everything crafted is exponentially better than that which isn't).

For example, a player with 100 alchemy is a much more powerful destruction magic user than a player with 100 destruction.

Destruction is not fine when a low level conjuration spell like bound sword can do more DPS and more damage overall than higher level destruction spells cast constantly. Or when an Atronach can rofl pwns a group of enemies in a minute that it takes 20mins to kill using fireballs.

is there a way to fix this?

Sure, nerf weapon damage since it's the people that are using weapons that are broken. If you really want a broken mage to create easy mode then either turn the difficulty slider down to the lowest setting and have fun 1 shotting everything or install a mod that makes mages just as broken as melee.