Its pretty inaccurate to say its stricter. Its just different. I would personally agree that it sets more specific hurdles to jump over, but saying that the ACGME rules are stricter is oversimplifying to the point of potentially sending the wrong message. ACGME rules simply are more restrictive as to what can and cannot be there (not that they are any harder to obtain.... theyre not. They're much more specific and you design the program to those specifications.)
If they have even a single residency program there the *only* way they add more residents is to either add peds residency or to change the laws. If they have residents, then they are locked unless they wish to pay the residents out of their own pockets. (They wont)
being qualified enough is a judgement call. There isnt someone grading residencies, though that would be an interesting job. This is a judgement call that certain places dont have the a) resources b) teaching staff c) variety of rare pathology d) patient load to support resident programs and offer a robust education.
But if a group of hospitals wanted to go and enroll their first residents they need to apply to the federal government. At the moment the OPTI system (a post-graduate education "oversight" system run by each osteopathic school) helps such hospitals get themselves ready for federal application. They apply to the government for funding for x y and z residency and the government inspects them for criteria a, b, c and d (as seen above) and decides how many residents they can take on in total, and in which fields they are allowed to place them. This process takes years (talking 3-5 years here) from initial desire to get residents to first entering class.
If your school doesnt have residencies affiliated with it you are at a very marginal disadvantage. You would probably notice it, but you'd probably assign *too much* value to it. It has less value than you'd think. From the point of view of future residencies, you do electives at places you want to go to and often you dont even need to rotate at the places you want to match to, as long as you rotate as similar places and have good LoRs from it.
WITH THAT SAID: if your base rotations are all at places without robust residency programs present you put your *education* at a significant disadvantage. People can talk all they want about how going to places with small or no resident presence is an advantage and you get more time with attendings. Those people are completely delusional. Residents are a *massive* boost to your education in the 3rd and 4th year. They are constantly reading, they have plenty of time to baby sit you and run through stuff with you. You get education and they get education (that you sit in on). They are usually a marker of a service busy enough that it *needs* residents, which means that there is more for the student to see. They often want to pass off procedures to you, attendings would rather do it themself. And they are your window to clinical research opportunties since they need to do research but rarely have the time, so your assistance is vital to them.