Before you post your conclusion on a matter, it would be really nice to share the reasoning on it, because so far you have given no explanation why you would want to spend 2-3 minutes in stealth non-stop in an arena.
My reasoning is that some people abuse it, yes, those people are an issue. But its 2-3 minutes, its not gonna kill you. In Guild Wars 1 there were people runing away from enemies to troll them, sometimes long time. So what? You know that they are stupid, that they are not worthy oponents. Same here. But as I said, by making some stealth breaker would just punish the rest.
For ex. I've seen shadow to wait those 2 minutes in 4v4 and than he killed one of the enemies who were left so we won the round. Was fun to watch.
That is what you mean isn't it? 4v4 arenas where people wait till its first kill wins?