...it gives them power where they normally have none.
Yes a job interview can be the worst thing to do sometimes. On both sides. If you are an interviewer there is absolutely no need to demean someone based on their experience or lack thereof. Some of the best people I have ever hired had "shade tree" computer experience and they ended up being better in most cases than the people that had previously worked for a legit company. That said I have also had the experience of the interviewee 110% sure they were getting the job because they were the best qualified. Turns out they didn't get the job because of the attitude. We hired someone with less experience because they were better team players and would not get bored the first year.
After attending literally hundreds of interviews, I can usually tell how the interview is going within the first 5-10 minutes. If I feel it is not going my way, I shift tactics and ask the really hard questions just to watch the interviewer sweat. Being married to someone who has been a recruiter and knows the laws inside and out I have learned how to put the potential employer on the hot seat just to see what kind of company they are. It can be great fun.
I had a room mate once that was a highly skilled programmer working for the defense industry. He made it his second job to interview with companies around the country, just so they would pay for his trip. He wants fresh lobster, he found a company in Maine to interview with. That was one hell of a lobster-fest weekend for all of us!