well I think locks are yearning for some passive dmg reduction, they try SL and find it's not as good as they'd like it to be for pvp, but some still stick with it regardless simply because it's passive unlike the other talents where you basically take more dmg but can stop that dmg for a short while, so instead of having constant spikes of dmg/ no dmg, they prefer going into the stagnant damage reduction talent although it is somewhat underwhelming atm, the talent is fine if people ONLY focus on the lock or the pet, if they double focus you and your pet it's not a damage reduction anymore it's a damage increase, since it was proven that having soul link equates at around 20% extra hp for the lock ( with and without pet ), if both you and pet take 100% of a dmg source, so you have 100% hp + 20% ( theoretical ) hp from using SL on a pet, so let's say you're at about 120% hp if you get attacked with the same attack on both the lock and pet ( ie: dots or cleave or wtv) , lock takes 100% of the attack, and pet takes 100% of the attack, basically it's an 80% damage increase to attack both the lock and the pet.