If you have a reach weapon and/or Enlarge that means it is not just current target to spend all your iteratives on but everyone in like 15 foot radius - and Wrath was never stingy with amount of hostile bodies on battlefield (even funnier with Long Arm and Lunge from TTT mod). Vital Strike does similar thing but feats could be costly, price of one miss in the chain is higher and it will underperform for anyone who wants many attacks for per hit dices, like Sneaks, Bane or Elemental Barrage.Can't kill a corpse, and if your target isn't already dead by the time the iteratives come around that usually means you're missing, which iteratives just make worse.
And it is not like there is many options if you want melee Lich with merged spellbook - all arcane spellcasting classes are low-bab, and among prestiges we have Dragon Disciple (medium bab, medium spell progression and that hurts), EK (full bab, 9/10 spell progression) and Hellknight Signifier (medium bab, full spell progression, no hellknight disciplines, trash abilities). For my eye, Elfritch Knight looks like the best deal here, with some 4 DD/Signifier on top depending on main class.