Okay, your argument is that, basically, in certain situations, it's okay to interrupt people. I'll give you that. I guess I can start to understand how there is an improved workflow in those situations.

I guess my ultimate complaint is: assuming you are having a conversation, what is the advantage? And it seems like your feeling is that there is none, that it's only advantageous in situations where you want to avoid conversation. That doesn't explain why people do it, though. I've been around people who were intending to initiate a conversation and did it through PTT anyway.

That said, the lack of in-protocol acknowledgment bugs me, too.