I agree with you Kimmio. There are lots of systemic problems associated with people with disabilities who wish to work. For example, contract work. I know many people with disabilities who would love to work full, or part-time, and have the skills to secure a good job. The problem is that contract work, (popular these days) while a problem for most people, can place people with disabilities who may have greater need for things like medical benefits, at greater risk. I know a woman with a MSc who has much to offer and has had to decline numerous job offers. Losing her disability pension was something she could handle. It was losing the other benefits like dental, medical, and so on, that created many challenges.
I also agree with the idea that anybody, whether they have a disability or not, can internalize a message of being worth less when that is communicated via a variety of ways - such as pay. For example, I have a couple of health science degrees, and at one point in my life was a regulated health professional. However once I became Matthew's mother any knowledge and experience I might have had was often immediately dismissed because I was "just the mom". I know there are times that I have certainly felt disempowered, voiceless, insignificant, and even lacking in knowledge (even when I was not) simply because I have heard the message so often that once I became the mother of a special needs child all the other parts of me were ignored.
Your point about poverty and disability often being synonymous is also a good one. There is a fair bit of research that supports that people with disabilities are much more likely to be poor. Poverty itself then brings with it all sorts of challenges that are not necessarily associated with the disability.