That said, in retrospect perhaps it would be nice if fewer employers "ghosted" former prospective employees.
Part of the reason that recruitment has become such a toxic part of the industry is that so many people are just selfishly playing the game now. If that's their attitude to first contact then how awful are they going to be later if you do end up working together?
A little courtesy costs nothing and makes the world a nicer place for everyone.
Normal? Absolutely not. It signals loud and wide that your time is not worth even a reply from the recruiter/HR and you are being treated as a disposable piece of crap. You can imagine how they would treat you if you actually got hired.
There is zero excuse for wasting the candidate's time like this. Even less today with all the "AI" automation the recruiting companies & HR uses - writing a form rejection e-mail is literally a one click affair.
Common? Yes. Professional? No. Courteous? Not at all.
The companies that get away with unprofessional or uncourteous behavior are typically the ones with lots of power in the job markets they operate in. That doesn't make this behavior acceptable any more than wage theft is, but it also doesn't notably harm these companies given the plentiful supply of candidates who are forced to put up with such behavior.
* ...for now.