What exactly are disabled people supposed to do?

My wife had her f2f today at Portland with a physiotherapist.
Arrived 10 minutes early, room locked, so I went and grabbed a chair from the hotel reception for her to sit in the corridor as she was feeling faint.
Assessors arrived at 8.30,(time of appointment) unlocked reception room and came out to tell us that as the form was so long it would take her a while to read through it so we'd have to wait.
Finally went in and had the grilling, seems they were trying to catch her out where ever possible.
What I don't get is that PiP is promoted as making disabled peoples lives easier, but from what they asked in questionnaire and again at the f2f it feels as if all people should be doing is sat in a room 24 hours a day and not doing anything to be eligible to qualify!
What about keeping people occupied with hobbies and interests, volunteering. She did ask my wife if she volunteered and she replied yes, she then proceeded to grill her on exactly what she did and for how long each day!
Her reply was a meeting once a month for an hour or so.
What about social inclusion and mental health, feeling a part of society, does non of this count as valuable?
I came away feeling very disillusioned with the whole system. Is this normal or were we just unlucky with our interviewer?

bud: I think you present a dilemma that many who are too ill to work (or work much) face when claiming disability benefit: fear that anything the claimant DOES do to try to be productive, aid their recovery, or just keep themselves going or sane may be used against them to claim that they're not sufficiently disabled to work or qualify for benefit.

Sitting/lying at home all day doing nothing may optimise one's claim - but it could be the worst scenario possible for one's future health/rehabilitation and is hardly conducive to anyone's mental health (surely?)

I'm not sure there's any way out of this dilemma IF an assessor bears the prejudice that 'if you're well enough to do X you're well enough to do Y'. Hopefully few assessors approach claimants this way, recognising that most claimants can do some things for themselves - just too few and/or to too poor a degree to count as 'normal'.