Is there any positive opinion about the disrupting the empyrean power?

My nav. player takes it on character creation, after reading it's description roughly ("Woah, I can summon mini-warpstorms? Awesome, I get this!"), he also made a nice backround story how he learns it, and uses it to make some dark eldar ships(which threatens the ships of his navigator-family) to crash into a planet. But before we can start the first adventure, we read the description thoroughly, and I say that power is really sucks. More precisely, it doesn't mean any threat to the enemy.

The description says: "Ships wishing to enter the warp, must travel out of the area, or risk damage ."
Damage is the keyword in this sentence.

Basically, with a not so powerful navigator(WP:45), you have 25% to add -10%/DOS to the test to enter/exit the warp. (Max -20) If the pilot fails it, it's ship takes a devestating 1 point of damage to it's hull integrity. So terrifying, I feel my legs shaking.
On the next levels the 1 point damage becomes 1d5, and on master level, 1d5+DOS, which is still lame, as you can't get more than 2 DOS.

So my question is:
Why any captain, who is not a coward worm, not go through a warp storm which causes 1/1d5/1d5+DOS point of damage to it's ship, which has 30-70 hull integrity?

I want to convince my player to keep this power, cause it's sounds awesome to create mini warp-storms, but it doesn't have any practical use, or serious threat factor, and he can't get another power until rank2, so I can't judge him when he said that he change it to any other.

So does anyone used this power with his nav effectively?

1) I don't get why you say you can't get more than 2 DoS with ther Mastery of the power, since a Navigator can have WP 55 + 20 for Mastery - 20 for the Diccifultyu of the power, that's 55% base. You can spend a Fate point for 65% chance, roll a 01, get 6 DoS then spend another Fate point to add an additional DoS for a total damage of 1d5+7 that ignores Void Shields and Armour (also remember each point of damage to the Hull is also damage to Crew Population and Morale).

2) The key here is that a SINGLE GUY without weapons is capable of doing 1d5+7 points of damage to every vessel on an enemy fleet within range. Again, A SINGLE GUY without firing any Component Weaponry. That's freaking powerful and badass!