Answer:
They wanted complete control over the colony's financial affairs.
Step-by-step explanation:
'Elected assemblies' were a group of people that were directly chosen by the colonists to rule all the legal matters within the colonies. This include things such as financial matters, land distribution, military, laws, etc.
If the Dutch West India Company allowed elected assemblies, they're afraid that the assemblies will create legislations that would be a hindrance for their interest within the colonies.