Why no "Mass Spell" feat?

[EOL]

Any wizard worth his salt is going to have at least a 16 int at first level, so the feat would always give at least three extra charges. It'd be like having three free quickened spells for the price of a single casting.

With the feat:

Round 1: Cast Extra Charged Vampiric Touch
Round 2: Touch enemy.
Round 3: Touch enemy.
Round 4: Touch enemy.

Without the feat to get the same effect:

Round 1: Cast Vampiric Touch
Round 2: Touch enemy.
Round 3: Cast Quickened Vampiric Touch
Round 3: Touch enemy.
Round 4: Cast Quickened Vampiric Touch
Round 4: Touch enemy.

I don't know. I suppose some DMs could find a way to make it work for them, but I'd never let it fly.

You can cast a touch spell and use it in the same round. From the SRD:

Use touch spell on one target [Standard][AoO: No]

Description: A combatant may take a move before casting the spell, after touching the target, or between casting the spell and touching the target. A combatant can automatically touch one friend or use the spell on itself, but to touch an opponent, the combatant must succeed at an attack.

Basically you can cast-move-touch, move-cast-touch or cast-touch-move. So the only advantage to the charge feat is reducing the possible AOO's from the actual casting (not the touching) to one rather than three.