The issue with your premise is mostly the assumption a bunch of not as qualified candidates got in RD,
NOT true. Everyone who gets into WPI is absolutely qualified. I was pointing out that at the top end there are candidates who appear that they should get in who are wait listed because the institution believes that they would not likely accept an offer of admission which would negatively affects the yield statistic. Consider the candidate who was accepted at Yale and MIT but wait listed at WPI — it is true, that candidate likely would not have accepted an invitation to matriculate at WPI, but this is not always the case. What I am saying is it appears that some applicants are apparently wait listed based on big data probabilities and not the pure merit of their academic credentials. That does not take away from the vast majority of students who absolutely are the cream of the crop and deserve a spot at WPI. WPI is not MIT. MIT rejects enough qualified candidates to fill their freshman class 4 times over. WPI has played bridesmaid to MIT for many years and WPI probably has more valedictorians enrolled than you can shake a stick at. The quality of the candidates accepted at WPI are fantastic, but it seems there is a new emphasis on yield, which can occasionally have unintended consequences.