I agree with you.. most people don't understand the difference between an internal alpha build and a "friends and family" Alpha (It's like a beta only it is much earlier in the development and invites are given to close friends and family of Blizzard employees, hence the name "Friends and Family" Alpha). People keep talking about Alphas like they publicly have to be talked about, THEY DON'T! A game doesn't HAVE to have a public beta either!
Blizzard dropped the "F&F" Alphas after Cataclysm, most likely due to people breaking the NDAs and posting images and info. I was in every F&F Alpha since Vanilla and followed the NDA strictly and I am currently in some betas that have NDAs that I follow as well. With MoP, I had to wait to get into the beta like everyone else though I was lucky enough to get in the second wave.
- - - Updated - - -
because they are Blizzard employees maybe? and they want to keep their jobs? I would :P