I am curious if you have ever studied economics, or just parroting what your social circle repeats. There is a very good reason you don't discuss politics, economics, abortion and religion in polite company - people can't remove what they were raised with and emotive response from logic. Economics isn't just money either, it's just the easiest way to introduce it to students - Economics is about efficient allocation of resources.
You are correct, economics isn't a science anymore than finance or psychology. But there are well established theories, laws and cause/effect relationships that can be relied on and its an entire model where changing one has flow on effects to soo much else we can't pin it down exactly.
Screw wall street investors, but keeping financial markets alive and reliable is a key pillar of our society - as an example how many of those students who had loans would never go to uni if they couldn't access credit? How many would never buy a house, or become homeless if they lost their job?
To go into deeper theory, look into your basic and complex multiplier and how they work in a recession. Forgiving a student loan doesn't increase consumption, just reallocate it. It looks bullshit because the rich get a payout and the middle class suffer, but there is reason and theory behind it.