The problem in my opinion is that folks afraid of posting treat chat channels like email and official record instead of a conversation. I like to post ideas, brainstorm, engage if I have a minute to respond to someone with a thought - kinda like being in an office - whereas many others seem to use it to blast out information after a lot of polish and they form a culture of announcements and no engagement, and get stressed whenever someone asks a question or actually replies.

Use tools for what they are good for and create a culture that makes each tool work best for your organization.