Well, you're kinda right but it will make folks mix up playstyles. I mean, if someone has a shield on back, you will need to come up with a different strat than looking for a backstab. It will add some variety to PvE too, provided they add more backstabbing enemies. There is basically a small window of opportunity to backstab. The more you pull it off the easy it will become. Try dropping your shield and circling the enemy up close, it is easier to get 4jcad.