[ganafagol]

This criticisim is slightly misguided. Let's say you have email notifications turned on too, and Joe could be standing next to you. Do you expect everybody to start email conversations with "whats up?" just so you can establish a confidential environment?

It's all about the topic discussed. Most of the time you just need to get the question out there. It's not confidential but you don't want to waste time with an extra round trip. So just write it down. No matter chat or email.

And sometimes something sensitive comes up. Then you take precautions, like booking a meeting, or having an understanding within management that your mail inbox/chat contents/.. are considered confidential (which they should) or similar.