If it was statted armor, it wouldn't work in the rom 3 class playing environment. Too many combinations for a one size fits all set. I mean if it was a single class system would be great, a mage set is a mage set, but in rom a mage set could mean M/s/p/d/r/k/w/wd and the potential new classes, and even if they did offer a set optimized for each class combo, who's to say it's going to work with your play style?
The appeal of the current system is that you can build the armor to fit your play style.
I primarily play as P/s or M/p, (depends on mood) but don't play the same as any other P/s or M/p I've partied with. I'm normally solo, or in small parties very seldom in large groups with dedicated roles assigned to each player. I heal, DPS, and very often tank so I need very different stats than a "real healer" S/p that runs with full groups and doesn't get toe to toe with bosses.