Fireball Pierce/Fork Question

Hey guys!

I've been planing a fireball build for quiet some time now. I wanted to run fireball with gmp and some pierce action. Now wiki says pierce on fireball will only create an explosion at the last target the projectile hits. So no matter what, piercing fireballs will only create one single explosion. Wiki also says, fork support linked to fireball creates an explosion at the initial target it hits as well as at the destination of the two forked projectiles. As i see it I get a sum of 3 AOEs this way whereas piercing only gives me one.

It's clear that a low level fork decreases the damage quite significantly but at level 20 and with 20 quality this handycap seems very little. On top of that pierce itself does not provide a huge dps boost to the projectile so i don't get why people are using pierce over fork.

Wouldn't it be better to just use fork over pierce to get 3 explosions and thus having more AOE coverage?

Thanks in advance!