This issue has been touched on before a couple of times. Memory stat is there as a form of balancing. Without it players could literally learn and field every skill and spell in game, you'll have every counter on hand and your character is basically a 1 man army making having party members pointless. Even D:OS/EE system is pretty much broken as ultimately, you can field all or majority of the skills & spells by mid level.
O yeah. In DOS EE 1 point in each spell school was super strong.
In DOS2 every point deducted from Intellect into Memory hurts your damage by 5%. But also, every point diverted from your main spell school into another is 5% damage lost (e.g. putting that point into Hydro instead of Pyrokinetics is 5% less fire damage). It makes one think a little more about which schools are worth spreading into.
