Job recruiter approaches prospective candidate to attend an interview and then ghosts them, accuses them of having an attitude when they try to follow up: 'I waited for a full 20 minutes, thinking maybe there was a technical issue or something'

Being ghosted for an interview you didn't even ask for is one heck of a situation to find yourself in. Sure, the balance of power is almost always squarely on the side of the interviewer, so they might get away with it, but they approached you, so what was the point anyway?

It's one thing if they're just running late or made an honest mistake, but to no show, no email, no call is unprofessional. Following that up with an air of superiority and acting like the candidate was in the wrong simply for pointing out that they made a mistake is downright absurd.

The recruiter should be on the back foot here since it is their mistake. They should be approaching the situation apologetically. Instead, they doubled down on their ego, refusing to accept they had made a mistake and making it seem as if the candidate shouldn't even be reminding them that they had missed a scheduled appointment.

That's one thing in any normal situation, but because of the aforementioned massive power imbalance when it comes to the interview process, even if their complaint came from some genuine place (it didn't), it's impossible to properly 

The lack of professionalism on display here is startling. And you have to wonder just why they haven't managed to fill that role yet.