(Originally a rant on twitter preserved here for easier reading)
This isn't rocket science — but it is apparently something that still needs to be said.
Putting requirements in your job advert that the job doesn't absolutely require gets you a less qualified pool of applicants.
It's that simple.
The unqualified bullshit artists will still apply. Because they and their dumb-ass egos don't care or understand that they're unqualified.
The mythical perfect candidate who actually has all of your kinda-would-be-nice-to-have "requirements" will probably still apply — because they still meet your actual requirements.
Then again they may just run away — because your random shopping list of requirements has demonstrated that you don't actually understand what the role needs in the job advert.
The only people a long list of requirements filters out are people who think you're telling the truth and really need somebody who ticks every item on your list.
Every unnecessary requirement on a job advert is literally making your pool of qualified candidates smaller.
Is fewer qualified candidates your goal? No? Then stop doing this.
Finally — as FJ points out
For example, see Tara Sophia Mohr's article on Why Women Don’t Apply for Jobs Unless They’re 100% Qualified.
If you fix your job advert you can make this whole class of problem vanish. Without forcing job applicants to change their behaviour to cope with a long list of unnecessary job requirements.