Why do mages get so much mana?

Int, their key stat, gives 5 mana a point, so they have no mana issues to begin with.  Pretty much all the mages passives are about getting more mana, raising their ratios on spells, or giving them accuracy.  These are not the passives and it is probably why I don't see too many mages.  Instead of getting better stats from their passives, mages can get mana which supplements an issue they don't have. 

 

They have enough passives to get an extra 25 mana per int and an extra 20% mana.  Assuming 350 int, that int gives you 12,600 mana, why the heck do mages need this?  They can also get 35% mana consumption and improved mana regen, but they need none of it.  Ok, maybe some of it, but this is a bit much.

Since the mana shield scales on max mana, it can be useful to raise that mana (preferrably plain int rather than mana) as high as possible.

Moar mana for meee.

MOAR.

But yeah , what is a Mages weaknesses? Taking damage from multiple targets and high powered physical skills. Mana helps with that since it scales up Mana Shield. The ratios on thier skills are fine

The thing is, there are so many mp passives that you can't realistically even get all of them along with other skills.