Balls are actually very hardy. There have been cases of them surviving for over a year with no food and minimal water in sub optimal conditions.
Humans and dogs are very hardy too but would you or if you had a dog, be healthy and thrive in a hole for years barely eating?
Many of the issues are indeed from poor husbandry but some are also from too much husbandry. That is to say being too over reactive to information available as a new owner. I would say just being lucky that you never had any infections on your snake is not any indicator that you had a adequate environment for your snake. You simply lucked out.
My first ball python when I was young suffered from a burn. I was arrogant and lazy and thought that it wouldn't happen but it sure did. My latest had mites when I bought him. I have seen people with the best intentions and those who have multiple reptiles and years of experience get respiratory infections, scale rot, mouth rot, and viral infections. It happens and it all can be traced back to husbandry. That includes diligence. Laziness is just as bad as negligence when it comes to animal care.
Proper husbandry does several things: It helps eliminate the possibility of stress that can lead to a weakened immune system and introduce harmful pathogens or conditions that lead to infection or disease. It creates a calm environment that is stable for a ball python that helps to lead to positive feeding, calmness, and improves taming including getting used to handling. The most important thing husbandry guidelines do is help to eliminate the trial and errors we went through years ago so that new owners get a great start in care and standardizes the care treatments so that when a professional or vet advises or examines a snake they can rule out husbandry as a cause of illness.
So yes, proper husbandry is as important to a ball python as it is to any other living creature. Just because something can survive in bad conditions does not mean they should be in bad conditions or that negligence without incident is a means to ignore thousands of man hours of research through trial and error.
I am not making this as any attack against you, I have made horrible negligent mistakes throughout the years owning pets but those mistakes taught me a lot about how to take care of an animal.
Think of it as insurance. You may never need it but you are sure glad you have it when you do.