Sorry you had bad experience. But I'd like to note here that many technical interviews that involve white board problem solving are nothing like this. I've attended interviews from a bunch of companies that do white board interviews. In almost all of them, the whole interview process went much smoother than this. Most importantly, nothing like "Not a word is said, they are clicking at their laptops, and staring at the whiteboard, as waiting for the genie to pop out of a bottle". If that happens, they are just bad interviewers.

White board interviews are supposed to be interactive. When I solve a problem, I always verbally say whatever is going on in my mind and share it with them. This does two things : 1. Helps me focus on the next steps instead of letting my mind race through different solutions, context switch often and lose track of my own thoghts. 2. Gives feedback to the interviewer so he knows I am on the right track and if not, give me clues (with or without him wanting to) that I can pick up on and proceed further.

In the end, my white board interviews always went like a conversation, a deep discussion about a problem that involves coming up with a solution and attacking it to see its pros and cons. I have come to appreciate the process itself because it tests several things like communicating to the team, problem solving, being open to other ideas etc.

Edit : I'd also like to note here that I didn't get these skills in my first interview. My first several interviews went horribly wrong like you mentioned. It is a skill that you need to invest time in. And you have to believe that the time you invest in this will pay off eventually. It did for me in several ways.