To get a good job :p
This argument applies for every other field, but you don't see civil engineers doing interviews past a week, and even with substandard hires, building are built just fine.
About 20 years ago, it was also common sense that a CS degree from Caltech means more than a 3 month Rails bootcamp, but now they're all treated the same.
That's the thing - in my country (Poland) nobody looks at grades anyway. The only exceptions are American companies that have offices there. Everybody else cares very much about the kind of University you graduated from (I think they mostly treat it as a proxy for general IQ and work ethic - best Polish schools for CS have admission rate of 7-10%), but don't care about grades.
> About 20 years ago, it was also common sense that a CS degree from Caltech means more than a 3 month Rails bootcamp, but now they're all treated the same.
Maybe because coding just got easier? I have a junior guy on my team that barely comprehends how computers work under the hood. However, he's still quite productive in an advanced/esoteric functional programming language. He just needs a little guidance by a senior to debug some less obvious issues or to review his designs to make sure they're not a performance catastrophe. Meanwhile, 20 years ago he'd just add a ton of segfaults to a C++ codebase and be fired...
Unfortunately, college results are not the most reliable. A in Algorithms class from a world-class CS university means something very different than the same A from some completely no-name Uni where teaching standards are very low and cheating is widespread and accepted. What's worse, even the people from top uni could be cheaters (it's just less likely) or rode on the backs of their colleagues in group projects.
Also, some people are like me and are not motivated to do well in school just for arbitrary and meaningless grades (I once got a grade corrected by the prof from C+ to A and didn't bother to go collect it, because what's the point of grades anyway?), while they will be very motivated in a job where they're paid good money.