That's a myopic and emotionally charged way of looking at it.
When I interview people, I ask straight forward, probing questions looking for how the candidate approaches the problem and the path they take to the solution. I don't ask trick questions, I don't mislead the candidate, and I help them as much as I can to get to a solution on their own. However, I look for and probe for information throughout the process. It's relatively easy to discern whether someone knows what they're talking about and can apply it versus someone who crammed for the interview. Moreover, if someone did cram for the interview and was able to apply the knowledge that quickly - great, I want to work with people like that.
Had someone asked me to implement a JSON parser in brainfuck - I would have got up and left. More generally - if someone asks me to use a _specific_ language in an interview; it's not someplace aware enough to know that 99% of the time the language is unimportant and not somewhere I want to work.
With all that being said - technical interviews are not "the worst thing ever". They serve a vitally important task of ensuring I work with competent and personable people.