The captain accidentally erased his family once by doing so, and becomes Captain Ahab, determined to bring them back even if it means destroying their home empire again
It was super disappointing. I mean, there's a slight handwave that because time was changed, maybe Kes' adventure never happened (which still doesn't explain how it happened in a timeline where Kes never ascended) but it's something you have to do OOC
it's especially bad because she name drops them, literally the same method they find to stop the torpedoes is used, and iirc even the same phase variance is required
except in that different timeline where he ends up Kim's father in law to his eternal chagrin