Is there a reason why they do this? Why don't they just tell you "im sorry you're not what we're looking for." Can someone clarify? Thank you!
They interview multiple people for the job, and then want to think back and see which is the best. Unless you're beyond exceptional that it makes sense to cancel any future interviews and hire you on the spot, they won't.
If you really bomb the interview, they might just reject you on the spot. But people are generally too scared to do that, so they let you down easy and with the safe distance of email.
Telling you no while you are there is giving you a chance to argue or even get violent. Sometimes they haven't decided until they meet all the candidates so if they said no then changed their mind it would be too late. Some might need to talk to other people before choosing.
I have interviewed people who had charm and I wanted to hire them so did others but after they left we talked about them and remembered they had no skills. We were more likely to hire someone on the spot than reject on the spot. The last I remember the boss asked me if I had objections to her in front of her. I said just her name, she had the same first name as me and I told him we had enough duplicates. She offered a nickname but we hired her and just called her first and last name.
Because they want to look at how you'd fit in the organization. Gather notes on your interview and make a decision based on everything about you. It wouldn't be fair to them or you if they made a decision like that on the spot.
saying, "I'm sorry you're not what we're looking for" will only cause an argument or a challenge from the applicant