Because they have told us that they are looking for this so that they can eliminate his advocate and adult social care so that they can have total control over him. They already persuaded him to drop his advocate last week and she was distraught when she spoke to us about it and raised it again as a safeguard issue with ASC where a 23 year old decided against this on the basis that he has "capacity".
In direct answer to your question, they said, "we will make sure that you never see him again", clearly they feel that guardianship or POA will allow them to cut out whoever they like. When his advocate went to see him at his flat last week, she reported that his parents could be heard telling him what to say in the background, the same when he rang us last week to confirm that the visit he pushed for himself was now cancelled.
My fear is that they can railroad a POA on the basis that he has capacity, and then remove all the very people who are actually adding value to his life and trying to allow him to have as full a life as he is able and to be as independent as possible.
Secondly, how sweeping are their powers under a POA even if they had this granted?