I think BOPO answered your question, perfectly.

I would like to give you another point of view.

Some heroes are labeled as Defense Type, but there Attack’s deal Damage based on Attack.

I will give you an example.

The hero named Grimskin - Orgyn Tribe - Epic

Grimskin is considered a Defense hero.

Grimskin Base Defense is very high.

Grimskin Base Attack is very low.

Check out Grimskin skills!

They do damage based on his Attack.

This is another reason why an Attack Weapon isn’t always useless for Defense hero.

Let’s pretend the game removed all Weapons from Defense hero’s.

Paragon would be ok because he is defense hero who scales Damage based on defense.

Paragon wouldn’t need the weapon.

BUT WHAT ABOUT GRIMSKIN?

Grimskin is defense hero, too.

Grimskin would suffer a lot with out the weapon because his Damage based on Attack.

I hope this helps you see why the game can’t change this.

Not all heroes are the same.

A lot of heroes are very unique.

hero type is decieving if not looked into hit

hero type has 2 meanings. either it refers to the base scaling (hp champion would have higher hp scaling)

or it eludes to the abilities and scaling multipliers

approach 2:

some ''defence'' heros have atk scaling abilities such as executioner's a1

however a defence champion like tayrel is a defence champion but only has [def] scaling on his abilities. 

this champion will NOT benefit from atk scaling