“Admissions stats also played a big role in the rankings formula. In 2003, ranked at 127, Northeastern began accepting the online Common Application, making it easier for students to apply. The more applications NU could drum up, the more students they could turn away, thus making the school appear more selective. A year later, NU ranked 120.” - https://www.bostonmagazine.com/news/2014/08/26/how-northeastern-gamed-the-college-rankings/

It also makes them money. Reject a $100 application and have $30 of labor and cots in it = $70 profit