As someone who runs a choir and community choirs events, it is a delight to see people being encouraged to enjoy singing - and you can see how very good it is for them. Singing is for everyone and anything that encourages that gets my vote.
But.......I deeply dislike the competitive element - this is totally unnecessary and is purely for TV producers, who believe that we cannot enjoy something without that. We need to let them know that they are wrong - we are bigger than that.
I also dislike the way he feels the need to have soloists - this too is unnecessary and pointless and it simply a way of adding another competitive element, rather than helping people to pull together to make a beautiful sound and share he joy that this brings.
And his choice of music is pretty banal - I have shelves full of the most wonderful choir music ranging from African chants to Mozart, from Beatles to swing - all of them much better than the pap that he feeds these singers.
But if it gets people singing and counters the idea that choirs are just for the middle classes ad musically educated, then bring it on.