They've hijacked the disability movement's rhetoric of the social model and independence as a way of saying a) the proposals will make people more independent (although they won't) and b) if you want to be independent then you can't possibly want to be on benefits.

Largely it is a lack of recognition that disabled people are at a great disadvantage and support is needed to overcome or mitigate some of that.

Parents receive child allowance but they aren't made to justify how every penny of it would be spent, they aren't targetted and shamed as lazy scroungers for taking child benefits.  Yet disabled people are made to jump through so many hoops, justify and evidence absolutely everything in the framework of a system that is designed not to support them but to use any opportunity possible to find reasons not to give support.