Recruiters get paid by the companies seeking employees. If these tactics do indeed provide employees, then the company pays them and they stay in the business.

Recruiters are selected for recruiting talent. As long as the talent stays for some length of time that the recruiter isn't blamed for poor retention, then the recruiter wins. This time is months, not years.

That's why recruiters who work these angles still exist. It's not like this is a new phenomenon. It has been going on as long as there have been tech-recruiters.

If they did get selected out, they would all be gone already.