But what happens when a person is busy and only has 30mn here and there? A huge blob of text for available times? What about when they get scheduled for a meeting 5 minutes after they send out that auto-generated blob? You could very well pick a time, set it aside, create calendar invites, etc... just to find out they _aren't_ actually available at that time.

It's a good point. There is a feature which allows the sender to "reserve times" in a one-off meeting. That way, they don't get booked before you have an opportunity to select a time.