Where are you now? Can you explain why you are getting low grades?
Your goal of becoming a doctor is not looking good right now. There are a LOT of health care jobs. When you go to the hospital you see a lot of medical professionals, and most of them are not doctors. You might want to check on what the full range of possible medical jobs are and which of them are more realistic.
"I am just wondering if these higher-caliber schools are too far of a reach"
It is very hard to know. However, I think that you have a chance and it is worth the trouble of applying. Your stats are very good, and it is possible that geographic diversity might be to your advantage. IMHO if you have any financial constraints then you might want to run the NPC and see if they will be affordable before going through the trouble of sending in an application.
You need to keep ahead in your classes, take every class seriously, study hard, and dramatically pull up your GPA.
If you were to go to a top 50 university, you will discover that students are just as smart as you and some are smarter, and they have a long history of working hard. Catching up at this point is possible but will be difficult and will require a lot of work.
Frankly your best bet to ever go to an Ivy League school at this point is to work hard for the rest of high school, improve your GPA dramatically, go to a "pretty good" (top 100) university, then try to get into an Ivy League school for graduate school.
I am pretty much in agreement with everyone else. I would not worry about it. I would let it go. However, I also would be THRILLED that your son has sensible and realistic expectations for universities to attend.
If the top universities have any difference at all wrt academics, the biggest difference is probably that some of them (MIT comes to mind) are more demanding and more stressful than other schools. No student should go to the most stressful school possible unless they want to do it. Just being a student with straight A's throughout high school doesn't mean that MIT or Caltech or Harvard would be a good fit.
I will also note that when I was a graduate student at a very selective university, there were other graduate students there who had done undergrad all over the place. I didn't happen to know anyone from Ohio, but I did know several very strong students who had done their undergrad at an in-state public university that is ranked very slightly lower than Ohio State.
My oldest slacked off at the end of high school, after getting her university acceptances, and got one 88 -- still a B+ but the lowest grade she had ever had in her life. No one cared and she did fine.
Continue with A's in your stronger classes. Try to avoid C's and definitely don't get any D's.