It does not defy logic. The ship is still part of the fleet and can potentially move in future.
And it hasnt become a free initiative sink! The fleet hasnt magically gained an extra initiative step, it has the same number it would normally have he simply has no choice about what one of them can do on its turn!
And to complain about behing outmaneuvered with Vorlons because of it and therefore its not fair is bordering on the insane. The Vorlon fleet is, bar none the toughest fleet in the game in terms of sheer surviveability, most of their mid range ships are pretty maneuverable and have a full forward arc. In that forward arc they generally pack the sort of firepower that other fleets wish they had! To counterbalane this it IS easy to outmaneuver them. What you seem to be complaining about is that you cant use your fleet filled with nothing but pricice weapons to go crit fishing and just ingore any ship that gets speed 0 rather than actually having to finish it off! If the example given too, the whitestar in question has lost its dodge so why not just SHOOT IT AND MAKE IT DIE. Problem solved.
To call a tactic 'unsporting' just because you happen to dislike it personally seems to me somewhat more unsporting.
Frankly I think too many people think good sportsmanship should mean 'being nice and letting me win'. Sportsmanship is, in my oppinion about being friendly open.
Don't rub it in your opponents face when theyre losing, but also dont whine and moan when your losing, take it like a grown up. If you win due to luck dont try to claim your opponent was an idiot and you blatantly outplayed him, but if you lose fair and square dont spend the next day and a half complaining about cheesy tactics and unfair ships and jammy dice rolling. Be open about what your doing and be friendly and understanding about genuine mistakes. If you move on to the firing phase and someone says 'oh hang on I forgot to move my fighters do you mind if I do?' let them if it wont really affect the game, dont be such a stickler for the rules that you come across as a jerk! Conversely though dont try to rewrite the rules mid game with 'oh but its just not common sense, it should work like this....'.
If a tactic is legal in the rules its fair enough, just because you didnt manage to counter it doesnt make it unsporting.