"I know it's really unfair because I didn't know any better mere weeks ago, and years ago I was a good textbook example of an intelligent person who'd keep mainly using his intelligence to rationalize whatever questionable decisions he made, but I just can't help it."
If we approach this from an economists lens the situation seems to change slightly. To an economist, a rational actor is someone or something that acts in her own self interest. Acting in ones own self interest is to make decisions where the foreseen benefits outweigh the foreseen costs. This means that even someone who is addicted to a hard drug and continues to use that drug is acting rationally as long as the benefits of continuing to use said hard drug outweigh the costs for that particular person.
Societally the values may not align but that doesn't mean that they are irrational. It just means that our foreseen benefits and costs are different from theirs. If you want to go down that rabbit whole, look into behavioral economics. They like to claim that people can act irrationally.
Economics is a highly applicable and general degree. It also teaches a person a new and rational way to think about the world. I would argue that the opportunity cost for an economist in the private industry is actually quite high and therefore the compensation for a job must also be high.
Wall Street, financial investment, banks, tech companies (Amazon, Uber, etc...) all have high demand for economists. Many of those jobs have a high value associated with them because of the scale of the companies and the profits that they produce. So if someone is looking for a job as an economist they have an opportunity to work at places that can pay them quite well. If this is the case then other businesses, not Wall Street, investment jobs, banks, or large tech companies, have to pay up in order to attract those minds to their particular sector of the private world. All because the opportunity cost (the next highest valued alternative foregone) is quite high for those people. If I am going to leave Chase Bank, where I work as an economist, I better have a good pay + benefits offer, or have some other intangible that is so attractive that it outweighs the pay cut.
Opportunity cost plays at least some role in the cost of everything that can be bought. That includes labor. That's my two cents.