The conclusion in the thread title is not one I thought up, but it implicated in some DWP research results which some here may find interesting.
It is not aimed at disability benefit claimants but I thought it relevant:-
research.dwp.gov.uk/asd/asd5/rports2009-2010/rrep605.pdf
Summary page 2
• a substantial proportion is unlikely to be readily employable. Achieving
employment outcomes is, therefore, quite distant for many, and unlikely to ever
be secured for some;
• many need sequential and cumulative interventions. Despite the established
‘work-first’ emphasis of public policies it is clear that for many within these
cohorts the path to employment is dependent on at least the containment, if
not the resolution, of several higher priority constraints. Consequently…
• routeways into employment are therefore often likely to be long and slow.
Many beneficiaries, particularly those with multiple disadvantages and within
the ACE Pilots, are therefore likely to face an extended period of intervention
and support before there is much chance of their becoming employable. Many
may not make it at all.