goals imply that achieving the goal will give you the success that the goal is meant to be a proxy of. That's why people go high into debt to obtain that degree - it's a goal, and the proxy for successful job/career. And yet, it seems to not be the case when they discover that this degree isnt the the golden ticket.
it's true that goals in games work - because it was designed to work that way. People setting goals in real life like they might be in a game (such as obtaining some sort of achievement, beating a "level" like passing school etc) might find that these goals don't actually reward them unless they're after intrinsic rewards.
If you fail a goal in games you can restart - which most of us will a few times in playing games. You cannot restart life so easially. We only get an unknown amount of years to live (statistically about 80, but up to about 120 is possible, or down to however many hours old you are right now) I've thought about going back to college several times in life, however as each year goes by the value of a different degree goes down because there is even less time I could use it. Though also as time goes by the cost of "useless degrees" goes down because I have more money saved (though it is saved for retirement).
Often if you fail to reach some goal in life it is gone for good. If you lose out in a promotion to someone else (who might or might not be good) you need to give up on that goal - either find a different promotion you can get next year, or a different job equivalent to that promotion (assuming you are worthy of the promotion)
Sure, degrees don't _guarantee_ you'll be successful. That's just a misguided expectation. You might even create constraints to help you get there.
Not all goals are misguided, and constraints can be misguided, too.
Do constraints somehow reward you more then? I've had both constraints and goals in my life, both have been rewarding and not just intrinsically.
In the US it's mostly the hope that tuition and time studying will have a positive return on investment in terms of future earning potential.