A larger issue is the empire has light speed travel so they can easily get on the other side.
I think the bigger issue is simply how close the ships where to each other. If that's standard then hyperdrive weapons are a big deal, if it's a mistake then at best you take down a ship some % of the time.
What about the devastation a couple of buckets of playpen sand would cause when accelerated to relativistic speeds, hypervelocity buckshot gun..
So really, it's not that nobody had the idea to build hyperdrive torpedoes. It's that they knew they would be fairly useless, and nobody would expect your enemy to kamikaze their sole remaining flagship into yours at hyperdrive speeds when they could accomplish far more damage to the target by simply crashing into it at normal speeds, as has happened nearly a dozen times in the SW movies. Holdo's act wasn't an act of strategy; it was an act of desperation, and worked far better than she expected it to.
Perhaps it required someone with the right force sensitivity to pull off.
Perhaps shields normally block these attacks and they turned them down to conserve fuel.
Perhaps when going past light speed ships normally just pass right on through normal matter. What happened was a never before seen effect based on failing to reach light speed in some highly unlikely fashion.
Perhaps it is reproducible, but requires tuning the shield frequencies. So it only worked do to the long period in very close proximity.
PS: Perhaps it's just a giant plot hole and showed up because someone at ILM showed a cool demo and they had to work that visual into the movie somehow.
Ehm...
“A long time ago in a galaxy far, far away...."
Couldn’t resist ;)
2) Star Wars has always worked that way. Having the ships continue coasting would violate rules established in the original Trilogy. See, e.g., ESB, where disabled Destroyers promptly lost stationkeeping.
3) The Resistance's largest ship barely damaged the Third Order flagship; a portion was split off but the flagship itself was still functional. It was the massive amount of debris from the Resistance ship breaking apart on impact that caused most of the damage to the remainder of the TO fleet. This strategy simply doesn't scale.
They're not meant to be lasers in Star Wars (: They're packets of ionized gas (a gas Lando and friends mine at Cloud City).
There are lasers in fact , but are less common and bigger weapons. Death Star's weapon is the prime example of course, but there are also others (right now I remember a laser weapon looking like a rhasadar being used by the rebels during the battle of Hoth).
But in cinematic terms the R2D2/C3PO double-act does make for some funny exchanges, so I guess that's what they were going for. So its kindof tropes first, world-building afterwards as an afterthought.
The organic ones aren't treated that well either.
Firstly, it would look ridiculous, and they would no longer seem menacing.
Second, and most important, so Phasma's toys sell better.
If you want a canon-consistent reason, umm... because most stormtroopers are grunts and the Empire doesn't really care about them.
Cylons beg to disagree.