There is no doubt that it is vital that Christians confess their sins as a prelude to repentance.
The disagreements begin in understanding what is meant by confession - in particular the question of to-whom the confession must be made: directly to God in prayer, or via some human mediator and authority?
Should confession be to a human person?
What light can be shed upon this by reflecting on the close analogy between human and divine Fatherhood?
What kind of confession is required of a human Father from his children and why?
Amongst other things, a Father wants to know that the child realizes what it is that is the sin.
This often need clarifying - e.g. kids think they are being punished for wreaking some trivial destruction - breaking a cup or scribbling on the wall - but actually they are being punished for concealing or lying about it.
They need to be taught that the proper behaviour is to acknowledge the accident, preferably pro-actively - and of course the parents must reward and endorse this acknowledgement (and perhaps suppress their annoyance at the destruction of a treasured possession, or the need to spend ten minutes on cleaning).
Further, the Father wants his child to acknowledge and agree that what she did is indeed a sin.
The Father doesn't just want his daughter to stop tormenting her brother as a form of amusement - but to stop because she can feel why it is wicked to destroy another person's happiness because she was bored, and nasty to provoke annoyance for fun - needs to understand that this is a recipe for family misery.
(Rant alert: In some ways this 'dog in the manger' behaviour of spoiling things for other people, of deliberately being annoying and enjoying the annoyance that is caused, is one of the very worst of sins. Not least because it so easily becomes habitual, indeed insatiable; and can so readily be justified by pseudo-moralism - 'she was being so smug/ arrogant - she needed taking down a peg - she deserved it'. (In effect: framing sarcasm, humiliation, aggression as an agent of divine retribution.) Not just families, schools, workplaces and other institutions - but much of the Mass Media, the internet and social networking is replete-with, quantitatively dominated-by, competitive dog-in-the-mangerism. Note: the term comes from a dog who insists on uncomfortably sprawling in the manger among the hay, so the cows cannot eat; the dog is prepared to put himself to considerable effort and discomfort merely to observe the cows annoyance.)
And a Father wants for the child to repent the sin and try his best not to repeat it.
But if or when the child does repeat the sin, to be proactive in confessing it.
So, there is an educational aspect to good confession, and the expected behaviour in response to repeated/ repeatable sins is different from first-time or one-off sins.
The need for education seems almost unavoidable. But the eventual ideal is to for education to be internalized, and confession to become self-policing.
Accepting that confession to God in prayer is mandatory; unless it is also believed that a human intermediary is essential for a confession to reach God, then on this basis, the main potential value of confession to a human is educational - which seems to imply that the confessor must be both wise and loving - the confessing person must trust their confessor, must believe the confessor wiser than themselves, must believe the confessor has their interests at heart.
The endemic shortage of wise and trusted confessors who are to us asif a loving Father, is probably a major factor in the way that confession as an ideal often asserted, seems so generally to become corrupted into rote, or avoided altogether (either not done at all, or deliberately not done properly).
Thus I do not believe that confession to humans is 'a good thing' as such - I would regard confession as potentially a good thing, under certain circumstances a good thing; but equally it is a thing readily capable of harm.
Just as a bad confession experience tends to be morally distorting to a child, so it would be to us; hence bad confession is worse than no confession at all.
As when a child is punished for the unintended accident of happening to break an expensive china cup; rather than for the real sin of throwing it at his sister's head.