Honestly I'm really surprised you have a degree in psychology and yet can't understand a 'wont' for one person is a 'can't' for another.
Life experiences, learned behaviour, plus all the possible pathologies that can make people think differently all contribute to people having different ideas of what's logical.
Even just a parenting class, lots of reasons why somebody might not want to attend, the most obvious being embarrassment, fear of being stigmatised, scared of facing the realisation that what they think is good parenting maybe isn't, preconceived ideas that they'll be dictated to or have their lives analysed and picked to pieces in front of others, and as has already been said, thinking 'well that's how I was raised I genuinely don't see anything wrong in that'.
Not saying that does happen at parenting classes, but some people might think that.
That's also just one example. We do all judge internally but the trick I'd guess for a social worker is being able to set that aside, consider what is needed to achieve the desired outcome
I don't think criticism, judgmental comments or 'you should be doing x y z' approaches are helpful because people
A get that probably from loads of other people in their lives
B it just makes them feel like failures and therefore incapable of change/improvement.
C worst case scenario they get pissed off and take it out on someone else! Perhaps the very child you're trying to protect.
It's an incredibly tough job, not just on this but in having to make incredibly difficult decisions with no knowledge that it's the right decision, criticism from the general public, press, politicians, other agencies...
I don't think it's for you, not just because of your approach, which training and possibly some counselling could maybe help with but I think it would make you incredibly stressed.
The scenario you're describing is an extremely mild one in terms of the kind of situations you're likely to have to deal with - hard drug addiction, child abuse of all kinds, severe mental illness...
How would you deal eg with a family who had a child with a serious illness who were refusing a treatment for the child on religious or ethical grounds? Returning a child to a previously abusive family? A child who is being abusive?
My parents had friends who were foster carers, they had cared for children in all the situations in that last paragraph.
Not a job I could do, living with having made a decision to leave a child with a family who then ends up dead? Removing a child from a family thinking it was the right decision and that child then descends into addiction, homelessness etc?
Awful decisions to have to make.
Understandable why social work is one of the professions with high rates of anxiety, depression, addiction, suicide.
I applaud anyone who does it but equally hope they would go into it with a compassionate heart and a strong mind.