Sounds like a self-center prick; a Gen Y idiot that NEEDS to be thanked. In many cases the candidate doesn’t have an email address to send a thank you as all communications for the interview come from them and it is a bit nerdy to track down the interviewer to thank them.
“the interview come from them”
should have been:
“the interview come from HR”
Absolutely true. Mid-level managers do not want to be bothered by incessant whining from interviewers that were discarded during the interview process. Usually, the person will say "Hello, my name is Bob, and I'm the ......". You visit with him for 20 minutes, and you never see him again. I've been shocked many times to find that the boss I have, when I'm hired, is actually the person who identified himself as a lower-level team member. This is done to evade the endless emails.