The thing is none of them said they are introverts. I've read the replies and I have not seen anyone saying they are introverts and is against meeting new people so please do not make lies up.
You said you read the replies. If you have read it you would see that most of the replies are about the fact that both you and the other flatmates are PAYING the rent to the university to live there, whilst your (ex) bf moves in RENT FREE. Do you understand that? If I was living in halls and my flatmates had bf's or gf's from before uni, I have no probs with them visiting (for example) for 2 days a week but if they do not go to the university. But move in permanently then yes I'd have a problem because that person is basically living RENT AND BILLS FREE which is not fair as I and the rest of the people living here are PAYING and they might as well be signing on at benefits, whilst living in a university halls of accommodation and how do I know that person is not here to steal my stuff if they are living rent free? Also the problem is the fact your bf would not have, nor would he be given the access key to the building so he would have to wait for you to be able to get back into your room and causing problems having to constantly asking someone to let him in. People would start to get annoyed that there is one person not contributing to the rent or bills. Theres a difference between someone visiting maybe once or twice a week and basically moving in permanently.
Also how would you explain that to security or even the university if and when they find out? Because somewhere down the line someone will definately grass you up and whistleblow the situation to the university, that there is someone not studying at the university, who moved in permanently to the halls of residences. How are you going to explain that to the university when they find out? Is your argument going to be (and to quote you) "are they all just complete introverts and hate the idea of meeting new people?" or to use your other "defense" (and to also quote you) "doesn't uni mean that the more people there the better?" Er but he is not studying at the university is he? You said in your first post he is/would be getting a job near the university, that means whilst you live on your student loans (and be in the same boat as everyone else) there will be one person who is in full time employment and living rent and bills free. In the eyes of the university that is not "the university gets more people the better". The more people at university = the number of people ENROLLED/STUDYING at that specific university.
That is what everyone is saying, or do you not understand that at all?
If you wanted to live your bf, many universities (that I looked at) have studio rooms or 1 bed flats designed for those who do not want to share with others etc, maybe that would have been a better place for you if that is what you were planning to do, if you were in those university "studio" halls of residence then yes by all means it wouldn't bother other people as much as when you are sharing everything else with them like kitchen/bathrooms/communal areas, but the studio accommodations, you still have to follow the university rules. The rules are there for a reason. You may not like them but its there for a reason. If you don't like it TOUGH.