As a college student who has only been recently officially diagnosed with two disorders that would have given me extra time on the ACT (ASD, and surprisingly, ADHD-combined subtype), I’d have to say no. (I also have chronic health issues that affect my cognitive abilities.) Even though I’ve known for years that I struggled with issues other people don’t have, because I didn’t have an official diagnosis it didn’t matter. Consequently, I did okay on the ACT, whereas with extended time, I could’ve done much better. Like the OP, I, too, have a tendency to not be able to finish some timed tests. Even though I was put in gifted in the 3rd grade, my yearly SAT scores were always around the 70th percentile, compared to my brother - who was also in gifted - who consistently scored in the high 90th percentile.
Whereas some graduate/professional school admissions tests do differentiate between whether you took the test under “normal” conditions or not (e.g., the MCAT), if this isn’t being done with college level tests, I would assume there’s a good reason why. I wouldn’t be surprised if there’s been a history of discrimination against intelligent students with disabilities at the undergraduate level, considering even graduate students worry about revealing that they have a disability. In fact, other students (both at the undergraduate and graduate level) often have no idea that their classmates receive extra time, because it’s no one’s business. The person knows, the professor knows (and perhaps the TA), and the school DSS office knows. Very few people outside of these roles will know students get accommodations.
As to whether it’s odd that the OP needed ACT accommodations, but not school accommodations, in reality, I bet that’s more common than you think. As I noted before, my standardized test scores were always lower than what my intelligence level was perceived to be; however, I made straight A’s. I only made two B’s in high school, and I didn’t struggle with exams then either, because, like the OP added, teachers often give you enough time to actually finish (and some will even let you finish the test after school or during lunch). (Plus, I became homeschooled during the second semester of 9th grade.) However, it’s a completely different situation with standardized testing. As we all know, they’re often incredibly strict. For example, if you have a broken bone (that is in a cast), it’s likely that your MCAT score would be marked. The same goes for if you have asthma or another condition that would require you to bring medicine into the testing room.
People with disabilities have enough pressure, people. Don’t guilt trip them for getting accommodations they need. And though the argument that more time would allow everyone to score better seems logical, it really isn’t. As the OP said, questions don’t answer themselves. Having too much extra time can lead to a student getting anxious while checking their work. Too much extra time can also be mentally taxing for some people. @fallenchemist brings up another valid point as well. A student with a disability often requires more time to do homework as well. So while you may be done in an hour, the kid in your class with dyslexia might, quite literally, need hours to get one assignment done.
Another thing about disabilities is that you may not even know you need accommodations until you get in a specific situation that shows you you need them (e.g., you’ve failed a test because you didn’t finish it; or you’re in a room with too many people or too many bright lights, which distracts you, makes you anxious, or frustrated; etc… And since testing accommodations aren’t retroactive, it’s better to take advantage of every accommodation you’re entitled to. I just recently submitted my paperwork to my school’s DSS office. I requested extra time (which at my school means 2x “normal” test time), the ability to take exams in a sensory-friendly environment, and others as well. Have I had issues with timed exams so far? Somewhat, though by the grace of God I’ve been able to keep a 4.0. I excel in an online class environment, which has also helped me as far as timed testing goes. However, I literally had to walk out of a midterm last semester. I was already frustrated and anxious and even having someone move can totally throw me off for hours. I just do better in a smaller environment because of my ASD. I remember the first time I took the ACT, I got nervous just because of the amount of people in the room. Not surprisingly, I did better - and felt better - the last time I took the test because there were probably only a dozen or so of us.
I congratulate the OP. Not only have they succeeded against the odds, but they did a pretty good job of both defending themselves and others with disabilities while also being respectful to people who were essentially attacking them.