So I got my Archer and Enchantress to 35, my Warrior is almost 31.

While leveling my Enchantress (From 30 to 35), I never ran out of mana. I mean, at all. I had good regen.
And the only 5 skills I used, that I felt had any importance, was Firestorm, Iceblast, Lightning, Heal and Ressurect.

After careful concideration, I realized, that I could spec all my stat points into DEX, equip a Bayou Bow, Croc Scale Leather, and Dead-Eye Derby, have insane DPS, and the exact same AoE as before, with the ONLY downside being, that I have to chug a mana pot every once in a while.
The gold in this game is so easy to come by, that I have enough cash to buy like two thousand Mana pots.

Intel does NOT raise your spell damage, nor does your gear.
My current Enchantress is running around with Zombie's Voodoo Fire Staff and Mamboza's.
All I have is Mana regen, whereas all Dex gear would boost my DPS, Armor, Crit, Hit and so forth.

I cannot seem to comprehend why ANYONE would spec Intel Mage.

I just don't know enough about the game mechanics to know, which is why I'm making this post, and hopefully get an answer.

My Warrior, runs around with his auto-attack, doing MINIMAL DPS because every class is PACKED with Knockback spells, and whilst I'm running to attack my target, I'm not actually doing any damage.

Here though, it's a bit clearer that if you specc all DEX, there are a few downsides.

Much lower armor and health is the main point, and chugging HP pots won't help you here because you might just get 1 shotted by bosses.
But with Armor and Evasion buffs, does this REALLY have to be a problem ?

I don't know, it just seems that all my three chars would be better if I specced every point into DEX, equipped them with a Bayou Bow of the Eagle (Which I have three of), and sent them on their way.

However, I'd have no variety in my gameplay.
So once again, this is why I'm making this post. So I can be "proven" wrong.
I can't see the downsides to speccing all three chars into DEX, so please show me.