It was formed into crystals because that is how the mineral was used by the Ark Tech. There are only so many ways that you can transport a mineral and use it. Gas, Liquid, or Solid. It isn't grasping at straws if you understand the lore of Defiance and that there is a entire orbiting debris field of thousands of ships and the stuff they carried around the Earth.
How exactly do you expect a miner to stop an object that is orbiting the earth from falling to the earth? Miners would be happy to have an easy source of Gulanite because they they wouldn't have to work hard at mining it. Ark Hunters hunt Ark falls and those hunters don't know what the fall will contain until it happens and the investigate.
It could contain a ship as in the Show, a pile of scrap controlled by the Ark Brain (The AI that controlled all of the Arks for the arriving aliens) or Gulanite crystals that the massive fleet had since it had to keep power for 5,000 years at least. For someone that claims to write material for RPGS you have a severely limited view of what could be possible given the lore stated about the world of Defiance.
The Crystals as ark falls are not a bad idea in the game. They are a perfectly fine idea but shouldn't be the only Ark Fall ever added to the game.
So what exactly do you think the Arks carried? Where did they keep their fuel and power source for 5,000 years? Gulanite is the mineral they used and they stored it in crystal form. Those crystals would have been carried by every Ark Ship and likely in bulk by cargo ships dedicated just to storing such things. Or even just a bunch of cargo pods.
All of that is orbiting the earth in the Ark Belt. Anything that is in the belt can fall to earth in an Ark Fall. It is a general term for stuff in the belt falling to earth and doesn't mean only the Ships.
It's because Trion went with the bullet sponge technique for Arkfall events rather than actually applying some real lateral thought to the idea.
Various reviewers listed this as the major criticism leading to boredom. Bugs can be forgiven...sloppy/bland game design cannot.
PS3 | ZenPro
There is only so much that can be done though. Look at how people now kill all the skitterlings. They do have some variety but a world event in a FPS pretty much has to be some type of bullet sponge though it would be interesting to have a vehicle based ark fall, but that would still be a bullet sponge if they allowed a Cerberus.
Even if they were ship parts instead of crystals you would still have bullet sponges in some form. Because it is a bullet sponge based game with the occasional road kill.