It's been done for balance purposes, so light classes can't re-stat great amounts of strength into dex from r8 armor (or even with magic cape which could hive them 50+ more dex). We would have archers and assassins hitting even stronger than they do now.
Please note that light classes would take the biggest advantage if it got changed back, since heavy classes have to distribute their stats on strength and dex over the gear requirements anyway, and magic classes still have to meet the strength requirements to wear weapon and cape (Bow and Daggers need much less strength than their armor)