Is it true that having no prior connections with the university makes me a less desirable candidate? I've just finished a conversation with a professor at University X. The majority of questions were on topics regarding the graduate admission. A quote that has both negative and confusing effects on me


  It is almost impossible to get accepted normally. Aside from sending in all the required documents, passing the tests (GRE, IELTS), having a good GPA score, etc. the only chance to be admitted is to have ongoing, strong research and collaboration with the faculty.


However, the admission criteria states that only the particular set of documents is required. Can it be true that having no prior connections with the university makes me a less desirable candidate?
I could be misreading this but it sounds like he means that to get in, someone actually has to want you.  I think he's saying it's unlikely you would be admitted to some sort of incoming class of new graduate students and then get assigned to an adviser as you likely experienced as an UG.

One big reason for the difference can be the money.  At many (most?) research universities, if they accept you as a PhD student, you will be funded.  But that funding has to come from somewhere.  If it's not from some big department pool but from an individual faculty member's grant money that they sweated to get, they're going to want to pick someone they like, not uncommonly someone they already know and have worked with.