When you have news as a burgeoning startup, it is like gold. Your startup's traction may be in large part due to having people just know you exist -- which if you've ever started a website/company, you know how hard that is.
That being said, for the press to break embargos just to have reported the news first seems sort of unfair to the entrepreneur who worker his/her ass off to get to the point to even be in a position to have press. Usually the reason the press breaks embargos is so they can "break the news first". Then, no other blog/press will cover it because its "dead news" regardless of it may have value to their readers -- even if they're a few minutes behind.
Obviously, its a bit of a gray area. However, to me, the majority of the time its competition amongst the press to "break the story" that really ends up hurting up-and-coming startups.