(To be clear, I have no insider information on this, I'm just interpreting what I have read.)
My take on this is that the corporations and intelligence agencies are in fact so threatened by the monsters that they are willing to work together (or some elements are), and their main intent is really to fight the monsters. If they weren't worried about losing entire colonies, then sure, maybe they'd start thinking about how to use the monsters to get ahead.
I think Kala's motivation in pursuing her personal experiment was scientific. Driven by her concern for others, but done in order to get facts. I think she was trying to identify and isolate details of how the monsters' HNA functions, to understand the cellular mechanisms that make the monsters work. She probably thought if she could transplant key portions of HNA successfully into Earth life, and the Earth life began to show certain expected properties, then it would be proof that she understands those mechanisms. I think that's what she wanted, based on the story as written.