Uh... I think the differences between countries realities, regulations, laws and bank behaviours are much more than you expect or assume. And I think you idealize banks and regulators too much and exaggerate their omnipotence or desire to "protect" the borrower or, as you said, the "country's economy" in general.
A loan to a borrower for banks works conversely like a deposit. In advanced countries, deposits have a ridiculous or practically zero percentage of income, encouraging people to invest money in the economy rather than putting it in banks. And developing countries are a completely different matter. The interest rates can be very high, but they usually barely cover inflation. This is offtopic, since the game part takes places somewhere in the USA, but all this still have an actual grounds even in the USA.
I cannot say or compare anything, because I have not live or visited the USA. If everything is so good and strict with the issuance of loans, as you described it, that let's say an 18-year-old will not be able to get a credit card and so on, then why is there are so much homeless people? Banks is a banks. They want to make money even if borrower is awful. They always find ways to fuck the person if he failed to repay.
MC is not a better candidate than Maya for getting loan, but in EP1 he says this:
mc "I can't accept this. I'll take a student loan and will find a way to earn some extra pocket money."
He is not working officially, has no confirmed income and pocket money making intended to live and survive as independent person and live his life in college, but it's not suitable for paying the loan he took. And... as we know Neil is not a person who can become a co-signer. House and the property of MC and Neil are not quite enough to cover something.
If you can explain me how come MC was able to get the loan being literally poor, while you think that Maya could not do that being in the same position, at worst, I would greatly appreciate it.
According to what you said and assumed, I think that Maya got it all right. Dad told her that he is taking the loan and she will become a co-signer, but he fucked her up (and Derek too) and made it so, that's it's Maya, who got the loan, while Patrick became a co-signer for her. Maya doesn't have property or any income and she is his daughter... she can't become a co-signer for him. Co-signer is a backup option for banks to take their money and shit back if the person who got the loan can't repay it anymore. Even im my shitty country years ago, when I was a co-signer for my sister loan, we had almost the same income, but the bank checked me, my documents, various certificates and statements several times more thoroughly than hers. At the moment (in my country)... a lot of people grab credit cards, live on them in debt and then take another card from another bank to repay the previous loan. Most of the time the only property they have is their apartments or houses in the suburbs. Their income is not covering expenses for a long time and all these percentages and other things only make the situation worse. But banks are not particularly worried, because if they throw a person out on the street and sell his apartment or house, they beat off everything and still stay with the profit.
And back to the game universe... Finnman bank was chosed on purpose. It's an additional clue of how and why he got this loan and why it was approved so easily, taking in mind some obstacles here and there. What do I mean? Often business and organizations cooperate with a certain bank. This often means preferential loans, much simpler registration of banking products (including credit cards) and a bunch of different bonuses for employees of the organization from a particular bank. Patrick's car dealership works with Finnman Bank. He could have taken this loan from any other bank, but no, he chose the bank with which his car dealership works.
In any case, any further reasoning will not be of much use, because it is impossible to get into the head of a DPC. References to real life and how and what works or doesn't work can help narrow down the number of versions and theories, but they can hardly help to understand how things are in the world of the game and what its author intended. It's exciting as the camera which Derek find at the end of EP9 and seems to become the very first matter in EP11.