In the US, Depending on your state this might not be true. Many of the 'Elite' schools are absolutely as you describe, but many of the state schools do cater to adult learners. This is particularly true in states which separate their Research Universities from their more teaching oriented Universities. Most of the latter do have night classes and other offerings aimed at adult learners. But the private universities with dreams of grandeur are looking mostly for the "traditional college student"
Now to the legalities. The Age Discrimination Act mandates any institution receiving federal funding from preventing someone from being able to participate[0]. So like a physical disability, if you only make stairs because "99% of people can walk" but cannot accommodate for someone in a wheelchair, you would be in violation of the Americans with Disabilities Act. Same thing with making a website accessible to the blind. By making your courses only available during business hours, you essentially are telling working adults "we are preventing you from participating in mandatory courses because you cannot be at work during the class." Work, mind you, that will pay their bills, support their family, and keep them out of absurd debt bondage upon graduation.
When you make class at 8AM for 1.5 hours, Monday-Wednesday-Friday, you are discriminating against working adults. It doesn't matter if the discrimination is intentional. Your very allowance of not offering a course wholly online without a mandatory attended lecture or just a night class is pure evidence that you do not want non-traditional students. How can an college believe that someone who works full time can make that work? Night classes are at least an accommodation and can work.
What I've found is technical colleges, since they're catered toward people going back to school, they do a much better job all around. Also since they are city funded and not a state run university through tax payers, they can hire real employees. So when I ask an administrative question that is very important, I don't get "uh I'm not sure, let me ask a staff member since I'm only a student employee! Can you hold for 10 minutes?"
I say this as a mid 20s return college student. My experience going back to college without the "stars in my eyes" so to speak, has really left me embittered by the system altogether. Schools act like autocratic bureaucracies that when they make a mistake all you get is an "oops sorry. Now deal with it lol." Also student employment is not only predatory (cause the pay is just garbage), but it's like they don't even train students either. If you want any answers, you have to wait to talk to one of the few people who has actually been hired on as an employee.
Higher education is structured for students going from high school to their institutions. They also assume students don't have full time employment or a family. So basically if you have either of those, the school doesn't care at all about your plight. They know your gonna pay off your loans and complete your degree. They prefer younger impressionable kids who are gonna waste a lot of time and money there instead.