You do realize that not all pets can CC you right? and even if they do there's a CD for that as well. Also, when rangers decide to have their pets use their CC skill that also cancels their healing skill so you can still continually attack a ranger in their downstate mode and kill them. and Yes i've used this in PVP and WvW but doesn't mean no one can kill me. Stealth nullify it, stability nullify it, hitting me only without doing finisher will nullify it.
So just because you found it hard to deal with one ranger doesn't mean everyone does. Just do better next time.