It’s a very good feature. It makes it so the user is in control of when they are unmuted, which is exactly what you want for privacy and security. It just means that presenters have to be on top of things and know when they are meant to speak. Yeah, that's the idea, to make the user control whether they are unmuted. But it's difficult when you have people in the audience who don't know how to unmute themselves.
What I find very odd is that this apparently only applies when the host has muted you to begin with! I don't understand that at all. And I just did notice in a Platform that there were still some people who I could unmute - maybe theym are ones who came in late and were not explicitely muted by me, I don't know.