As the guy above has stated. There are way more times when Vendetta is up and you can't use it right that second to get the extra uses. Some of you are acting like every 35 seconds you can just press vendetta without a delay.
As I've said and many others have said, you literally only need 5 seconds where Vendetta is not being used for that relic to be a complete bomb and total DPS loss. The rupture relic doesn't suffer anywhere near the amount of diminishing returns and in fact gains value when a) you can't hit the target but have rupture up and b) have more than one rupture rolling.
MA relics lose (relatively) all their DPS value anytime Vendetta is not on cool-down. Period.