I’ve long thought the same thing — the ACT and SAT should go away, not just for the reasons you listed, but also because such scores do not reflect the student’s gumption, by which I mean that student’s determination to work and to achieve. It only measures potential.
I did well on the ACT, but my grades did not reflect that score. I went straight to college thinking to myself that hey, I’m really smart, so I don’t have to work as hard as the other kids…and promptly flunked. I had high potential, but my level of effort was next to nil. The other students I knew who had lower ACT scores but higher grades did much better than I did.
Even if the SAT and ACT were somehow changed to allow for different cultures, economic status, and other forms of adversity, all they can ever really measure is potential. Even worse, not only can those who score higher think they don’t have to work as hard, too many who score lower wind up thinking “I’m not as smart as those other students. Maybe I should just work at Wal-Mart instead of going to college.”
The ACT and SAT should be canned. Period.