Can you sing? No. Goodbye. Yes. Go through.
It is that simple. Someone who has no singing ability should not be put through and is only put through so people can laugh. That is disgusting. More so when it is a vulnerable person with no singing ability. That is the key question. Can they sing or not. Putting someone through who can't sing is not right. Because they are only going through to be laughed at.
And re the whole 'choice' thing. You make a 'choice'. Well, there's choice and there's choice, frankly. A person with mhp may make a 'choice' to go on a tv show and be ridiculed, time and time again. A person with dementia may make a 'choice' to walk down the street in their nightie. A child may make a 'choice' to run across a busy road. A drunk may make a 'choice' to jump into an icy river in the middle of the night for a skinny dip. There are myriad reasons why a 'choice' may not be a choice at all. Do we say their choice. Or do we look at people and see the reasons why they may need to be supported in their decision making?