I don't have a problem with checking whether disabled people are able to work. I have a mental health problem, and I'm able to work now. However, when things got really bad I did claim benefits for a few months. I didn't have a problem going to an assessment, as I don't think the government should give money out to anyone who asks.
Not all disabled people are victims - many would love to make a contribution to society and would benefit from being helped into work. If someone can, for example, sit comfortably, then call centre work may be suitable and may give that person a purpose, social life, dignity and all the other reasons why people work.
However, assessments have to be fair. A friend's brother has a mental age of 8 and has been forced to go to multiple interviews. That's ridiculous. However, plenty of others can work - in my school we have a teacher in a wheelchair (yes, shock, horror to those who think disabled people are victims - she has a degree and a professional job!), and lots of people with mental health issues can work given enough support.