Indeed Software Development Manager interview questions

So I had a first level coding interview with a developer. It went well and I was invited for the second interview with the PM. So it was going when, one of the questions was how can we make it easier for employers to find candidates. So I replied if 100 candidates apply for a position, we will automatically give a score for each resume based on how relevant the resume is to the job description. He didnt like the answer and said to me that is unfair to some candidates. I really dont understand why that is unfair. When I apply through indeed, it gives the jobs in some order, from the looks of it, I can understand it lists those that are similar to my resume on top. To rank it like this, they should have a score internally of how my resume and this job match. If it is unfair, then is it not unfair to order jobs based on relevance? I can say for sure that it does feel unfair to me to get denied based on this answer.