I would be willing to bet that this was a topic that was hotly debated on the dev team at some point. Should they go with a Star Wars feel or a Star Treck feel? Star Treck generaly goes with the laws of phisics. Star Wars has fighters in space swooping in to attack and banking for turns in space. I think they thought the star wars feel would give the game more action and entertainment value but I think the anoyance value overbalances it hahaha.
The simple answer is, ships DO turn in this game without moving. Set a group of ships to phase jump in formation, then move them all really near the phase line, then click on the planet. Watch them turn IN-PLACE to line up! Lol
More seriously, I know you are talking about ships in actual combat. And I agree, to a point. What this aspect does is it forces you make the call on whether to retreat early on. If you have e.g. a level 10 battleship that you *really* want to keep, and it's taking a severe beating, you'd better get it out of there as soon as the shields drop (or even sooner, depending on how fast it's getting hurt). Fortunately, battleships can fire their autocannons and lasers while moving, so you can start retreating them "just in case" and still have them provide the equivalent firepower of a big frigate (depending on battleship class/level). It also makes the battleship turning research (under Combat) more meaningful.
As for the case of LRMs... ouch. Too bad they're not a very maneuverable craft - they tend to get eaten up very easily once they start taking fire, regardless of what's shooting. Realistically, they shouldn't even be close enough to the gauss cannons for this to matter! And again, you need to plan extra-carefully depending on how much you care about the assets you're retreating.
That's one thing I actually like about this game: the concept of tactical commitment. Once your forces have started to phase jump, they're committed - there's no turning back. You HAVE to send them. You HAVE to make sure they do as much damage as possible, even if they end up losing. Retreating is still possible, if you warp into a sector without a phase inhibitor (or destroy it), but generally the only ships durable enough to retreat are battleships and kodiaks.
I think the element of turning while moving adds to the tactical diversity of the game, and makes foresight and careful planning more valuable. There are plenty of strategy games out there where it is insanely easy to retreat; this is not one of them.
As advice for retreating in general -- consider keeping your less-valuable ships (Cobalts, Gardas, LRMs, Krosovs) in combat with enemy forces while you back out your valuable ships -- battleships, most importantly, and Kodiaks if you can withdraw them. It's better to save your most important ships - and destroy some more enemies in the process - than to retreat the entire fleet and allow some sneaky bombers to destroy your beloved flagship.
This is an interesting thread though

I giggled at the Star Trek references; I'm a Trekkie.
-allquixotic