Simple answer? Law of Unintended Consequences.
I think Acid is a perfect example here. In the early build, it was completely useless, because to survive you had to alpha-strike, and Acid is a delayed-action weapon which is completely useless in an alpha-strike. So people complained.
So they buffed Acid - and because it seemed cool, they added a couple of weapon mods to the Pandas which used Acid too.
Now Acid’s a beta-striking weapon that can kill you in 2 turns, but it’s so powerful in the hands of the Pandas using the spiffy new weapons the devs thought up that it damn near breaks the game.
So no-one’s satisfied, because no-one apparently thought through what giving 3-shot Acid Lobbers to Chirons would do in the new Acid environment they had just created.
I don’t want to diss the devs here, but it does sometimes feel like this game is being built by people who don’t really quite understand how to properly balance a game. It feels like they introduce something, see how it works, then panic and take it to the other extreme. Hopefully, by the time Steam comes online, they’ll have found a middle ground and everyone will be happy.