Apparently you're under the impression that biometrics are foolproof. That's a mistaken impression.
Even if they were, and they could be kept secure, every judge in the US is supposed to get these powers? So what about judges in the UK, EU, Israel, Russia, China, Japan, Korea, Iran, Iraq, India, Pakistan and so forth? What if the laws differ in some countries so they don't require a judge but anyone who works for the government should able to decrypt?
If a US company provided a backdoor for judges in one country, other countries are going to say "give us the same or we will ban the sale of your product in our country".
I don't know that I agree that judges - even with a proper court order - should be allowed to search someone's phone. Why? There's no precedent for this in the past - look at how much information someone's phone carries. That's basically the equivalent of a blanket search warrant covering not only your home, car, office, etc. but also your mind. I mean, in the past if someone told me something important I have to memorize it. Now I don't have to bother, because if they told me in a text message I know I can find that text again, even five years later. Why should judges have unrestricted ability to search my memory? Because it makes overly fearful people a little less afraid when they read about the latest terrorist attack, knowing that the government has unlimited power to snoop?