Mihalik says it best :
RNG is precisely what causes people to react, there are times where I miss a shockwave, or a disarm is parried when I am at low health so then I have to Shield Wall (whereas if it wasn't parried I wouldn't).
As a rogue you have plenty of other options besides landing a stun to win a fight, just like how Casters / ranged have multiple tools to combat melee besides CC. Everyone loses to bad RNG sometimes, but more often then not it will always play in your favor.