As a teacher, I have found that not telling people in advance what we'll be covering/discussing ahead of time keeps interest. Sometimes it's very difficult to stay silent about it when it's something I'm passionate about, but I remember the disinformation of the internet is at the fingertips of my younglings' hands. If I say it too far in advance, I guarantee about 35% of the class will look at something that is probably wrong on Google, and it's alot harder to correct than to teach anew.
In my head (granted, it can be a frightening, disorganized mess) the goal is similar here. If they show something that people really really take a liking to, that's fine and good until later in development when that system and another one just don't mesh and make an enjoyable experience, and it needs to be altered drastically or even completely omitted. Then they go through alot of heartache getting people on board with the new UI or whatever they changed. It just makes sense, when you REALLY REALLY think about it to remain silent about most everything until they KNOW it is an outstanding piece of work.
In regards to the losses of some staff... That's normal. I just wish people didn't have to try and drag the name of the company through the mud, that's slander. There are just shitty supervisors out there, I've had a number of them myself. I had a wrench thrown at my head at a dealership, (I didn't stick around long after that) I was forced into doing things way way way outside the scope of my job description when I worked for a treatment facility (I was a counselor, and I wound up doing construction in the basement of the group home.) I'm saying this because those were great great companies to work for, I just had some asshat in charge who'd never done my job before. If it's something you can learn to live with, do so. If you can't, you find something else (It was a good sized wrench, I think 22mm head) Normal ebb and flow. In and out.
I guess I don't know if everything I spoke on fits into this thread, but it just kinda flowed out through my keyboard... cheers, peers!