"Nonverbal people are communicating, they can use AAC devices!!! The only reason a nonverbal person can't communicate functionally is because the people around them are not trying hard enough!!!"
(Sometimes this statement in some situations is true, but I am talking about when it is not true)
Have you tried using symbol based AAC? Do you know what any AAC apps are called? Do you know there is different types of AAC? Have you even actually looked at the home page of a high tech AAC device?
For someone without impaired communication, I think it would probably take about 1-2 months if not more to fully learn their way around a high tech AAC page set.
Now imagine an illiterate person, a person who has severe fine motor delays, a person who does not understand what people are trying to get them to do when given an AAC device, a person who doesn't understand any language at all, a person who doesn't understand what AAC is or even the concept of communication in the first place, a person with little interest in communication.
Can you imagine that person, handed an AAC device? Do you seriously think they will suddenly starts expressing their thoughts in great detail?
Have you ever talked to someone who used to fit the criteria of being profoundly autistic or someone who's profoundly autistic caregiver? Have you listened to how many hours of therapy a week they have for their communication? Sometimes five hours a week and sometimes even more. Do you know that? Do you know how hard some peoples caregivers try? How much they wish their child could be able to communicate functionally?
How much money they spend on AAC apps? Do you even know how much an AAC device costs? A SGD? Thousands.
Stop calling caregivers lazy when they say their child can't functionally communicate their needs. You have no idea how hard they are trying.